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  1. Sohail M, Mudassir, Minhas MU, Khan S, Hussain Z, de Matas M, et al.
    Drug Deliv Transl Res, 2019 04;9(2):595-614.
    PMID: 29611113 DOI: 10.1007/s13346-018-0512-x
    Ulcerative colitis (UC) is an inflammatory disease of the colon that severely affects the quality of life of patients and usually responds well to anti-inflammatory agents for symptomatic relief; however, many patients need colectomy, a surgical procedure to remove whole or part of the colon. Though various types of pharmacological agents have been employed for the management of UC, the lack of effectiveness is usually predisposed to various reasons including lack of target-specific delivery of drugs and insufficient drug accumulation at the target site. To overcome these glitches, many researchers have designed and characterized various types of versatile polymeric biomaterials to achieve target-specific delivery of drugs via oral route to optimize their targeting efficiency to the colon, to improve drug accumulation at the target site, as well as to ameliorate off-target effects of chemotherapy. Therefore, the aim of this review was to summarize and critically discuss the pharmaceutical significance and therapeutic feasibility of a wide range of natural and synthetic biomaterials for efficient drug targeting to colon and rationalized treatment of UC. Among various types of biomaterials, natural and synthetic polymer-based hydrogels have shown promising targeting potential due to their innate pH responsiveness, sustained and controlled release characteristics, and microbial degradation in the colon to release the encapsulated drug moieties. These characteristic features make natural and synthetic polymer-based hydrogels superior to conventional pharmacological strategies for the management of UC.
    Matched MeSH terms: Nanoparticles/administration & dosage
  2. Dong J, Tao L, Abourehab MAS, Hussain Z
    Int J Biol Macromol, 2018 Sep;116:1268-1281.
    PMID: 29782984 DOI: 10.1016/j.ijbiomac.2018.05.116
    Osteoporosis is a medical condition of fragile bones with an increased susceptibility to fracture. Despite having availability of a wide range of pharmacological agents, prevalence of osteoporosis is continuously escalating. Owing to excellent biomedical achievements of nanomedicines in the last few decades, we aimed combo-delivery of bone anti-resorptive agent, alendronate (ALN), and bone density enhancing drug, curcumin (CUR) in the form of polymeric nanoparticles. To further optimize the therapeutic efficacy, the prepared ALN/CUR nanoparticles (NPs) were decorated with hyaluronic acid (HA) which is a well-documented biomacromolecule having exceptional bone regenerating potential. The optimized nanoformulation was then evaluated for bone regeneration efficacy by assessing time-mannered modulation in the proliferation, differentiation, and mineralization of MC3T3-E1 cells, a pre-osteoblastic model. Moreover, the time-mannered expression of various bone-forming protein biomarkers such as bone morphogenetic protein, runt related transcription factor 2, and osteocalcin were assessed in the cell lysates. Results revealed that HA-ALN/CUR NPs provoke remarkable increase in the proliferation, differentiation, and mineralization in the ECM of MC3T3-E1 cells which ultimately leads to enhanced bone formation. This new strategy of employing simultaneous delivery of anti-resorptive and bone forming agents would open new horizons for scientists as an efficient alternative pharmacotherapy for the management of osteoporosis.
    Matched MeSH terms: Nanoparticles/chemistry*
  3. Yusoff N, Rameshkumar P, Mohamed Noor A, Huang NM
    Mikrochim Acta, 2018 04 03;185(4):246.
    PMID: 29616348 DOI: 10.1007/s00604-018-2782-x
    An amperometric sensor for L-Cys is described which consists of a glassy carbon electrode (GCE) that was modified with reduced graphene oxide placed in a Nafion film and decorated with palladium nanoparticles (PdNPs). The film was synthesized by a hydrothermal method. The PdNPs have an average diameter of about 10 nm and a spherical shape. The modified GCE gives a linear electro-oxidative response to L-Cys (typically at +0.6 V vs. SCE) within the 0.5 to 10 μM concentration range. Other figures of merit include a response time of less than 2 s, a 0.15 μM lower detection limit (at signal to noise ratio of 3), and an analytical sensitivity of 1.30 μA·μM-1·cm-2. The sensor displays selectivity over ascorbic acid, uric acid, dopamine, hydrogen peroxide, urea, and glucose. The modified GCE was applied to the determination of L-Cys in human urine samples and gave excellent recoveries. Graphical abstract Spherical palladium nanoparticles (PdNPs) on reduced graphene oxide-Nafion (rGO-Nf) films were synthesized using a hydrothermal method. This nanohybrid was used for modifying a glassy carbon electrode to develop a sensor electrode for detecting L-cysteine that has fast response (less than 2 s), low detection limit (0.15 μM), and good sensitivity (0.092 μA μM-1 cm-2).
    Matched MeSH terms: Metal Nanoparticles/chemistry*
  4. Rahman INA, Attan N, Mahat NA, Jamalis J, Abdul Keyon AS, Kurniawan C, et al.
    Int J Biol Macromol, 2018 Aug;115:680-695.
    PMID: 29698760 DOI: 10.1016/j.ijbiomac.2018.04.111
    The chemical-catalyzed transesterification process to produce biofuels i.e. pentyl valerate (PeVa) is environmentally unfriendly, energy-intensive with tedious downstream treatment. The present work reports the use of Rhizomucor miehei lipase (RML) crosslinked onto magnetic chitosan/chitin nanoparticles (RML-CS/CH/MNPs). The approach used to immobilize RML onto the CS/CH/MNPs yielded RML-CS/CH/MNPs with an immobilized protein loading and specific activity of 7.6 mg/g and 5.0 U·g-1, respectively. This was confirmed by assessing data of field emission scanning electron microscopy, X-ray diffraction, thermal gravimetric analysis and Fourier transform infrared spectroscopy. A three-level-four-factor Box-Behnken design (incubation time, temperature, substrate molar ratio, and enzyme loading) was used to optimize the RML-CS/CH/MNP-catalyzed esterification synthesis of PeVa. Under optimum condition, the maximum yield of PeVa (97.8%) can be achieved in 5 h at 50 °C using molar ratio valeric acid:pentanol (1:2) and an enzyme load of 2 mg/mL. Consequently, operational stability experiments showed that the protocol adopted to prepare the CS/CH/MNP nanoparticles had increased the durability of RML. The RML-CS/CH/MNP could catalyze up to eight successive esterification cycles to produce PeVa. The study also demonstrated the functionality of CS/CH/MNP nanoparticles as an eco-friendly support matrix for improving enzymatic activity and operational stability of RML to produce PeVa.
    Matched MeSH terms: Magnetite Nanoparticles/chemistry*
  5. Azizi S, Mahdavi Shahri M, Mohamad R
    Molecules, 2017 Jun 08;22(6).
    PMID: 28594362 DOI: 10.3390/molecules22060831
    In the present study, ZnO nanoparticles (NPs) were synthesized in zerumbone solution by a green approach and appraised for their ability to absorb Pb(II) ions from aqueous solution. The formation of as-synthesized NPs was established by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and UV-visible studies. The XRD and TEM analyses revealed high purity and wurtzite hexagonal structure of ZnO NPs with a mean size of 10.01 ± 2.6 nm. Batch experiments were performed to investigate the impact of process parameters viz. Pb(II) concentration, pH of solution, adsorbent mass, solution temperature, and contact time variations on the removal efficiency of Pb(II). The adsorption isotherm data provided that the adsorption process was mainly monolayer on ZnO NPs. The adsorption process follows pseudo-second-order reaction kinetic. The maximum removal efficiencies were 93% at pH 5. Thermodynamic parameters such as enthalpy change (ΔH⁰), free energy change (ΔG⁰), and entropy change (ΔS⁰) were calculated; the adsorption process was spontaneous and endothermic. The good efficiency of the as-synthesized NPs makes them attractive for applications in water treatment, for removal of heavy metals from aqueous system.
    Matched MeSH terms: Nanoparticles/chemistry*
  6. TermehYousefi A, Tateno K, Bagheri S, Tanaka H
    Sci Rep, 2017 05 09;7(1):1623.
    PMID: 28487527 DOI: 10.1038/s41598-017-01855-5
    A method to fabricate a bioinspired nanobiosensor using electronic-based artificial taste receptors for glucose diagnosis is presented. Fabricated bioinspired glucose nanobiosensor designated based on an artificial taste bud including an amperometric glucose biosensor and taste bud-inspired circuits. In fact, the design of the taste bud-inspired circuits was inspired by the signal-processing mechanism of taste nerves which involves two layers. The first, known as a type II cell, detects the glucose by glucose oxidase and transduces the current signal obtained for the pulse pattern is conducted to the second layer, called type III cell, to induce synchronisation of the neural spiking activity. The oscillation results of fabricated bioinspired glucose nanobiosensor confirmed an increase in the frequency of the output pulse as a function of the glucose concentration. At high glucose concentrations, the bioinspired glucose nanobiosensor showed a pulse train of alternating short and long interpulse intervals. A computational analysis performed to validate the hypothesis, which was successfully reproduced the alternating behaviour of bioinspired glucose our nanobiosensor by increasing the output frequency and alternation of pulse intervals according to the reduction in the resistivity of the biosensor.
    Matched MeSH terms: Nanoparticles/chemistry*
  7. Supramaniam J, Adnan R, Mohd Kaus NH, Bushra R
    Int J Biol Macromol, 2018 Oct 15;118(Pt A):640-648.
    PMID: 29894784 DOI: 10.1016/j.ijbiomac.2018.06.043
    Magnetic nanocellulose alginate hydrogel beads are produced from the assembly of alginate and magnetic nanocellulose (m-CNCs) as a potential drug delivery system. The m-CNCs were synthesized from cellulose nanocrystals (CNCs) that were isolated from rice husks (RH) by co-precipitation method and were incorporated into alginate-based hydrogel beads with the aim of enhancing mechanical strength and regulating drug release behavior. Ibuprofen was chosen as a model drug. The prepared CNCs, m-CNCs and the alginate hydrogel beads were characterized by various physicochemical techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer studies (VSM). Besides the magnetic property, the presence of m-CNCs increased the integrity of the alginate hydrogel beads and the swelling percentage. The drug release study exhibited a controlled release profiles and based on the drug release data, the drug release mechanism was analyzed and discussed based on mathematical models such as Korsmeyer-Peppas and Peppas-Sahlin.
    Matched MeSH terms: Nanoparticles/chemistry*
  8. Azlin-Hasim S, Cruz-Romero MC, Morris MA, Cummins E, Kerry JP
    Food Sci Technol Int, 2018 Dec;24(8):688-698.
    PMID: 30044138 DOI: 10.1177/1082013218789224
    Antimicrobial coated films were produced by an innovative method that allowed surface modification of commercial low-density polyethylene films so that well-defined antimicrobial surfaces could be prepared. A Pluronic™ surfactant and a polystyrene-polyethylene oxide block copolymer were employed to develop modified materials. The Pluronic™ surfactant provided a more readily functionalised film surface, while block copolymer provided a reactive interface which was important in providing a route to silver nanoparticles that were well adhered to the surface. Antimicrobial films containing silver were manufactured using a spray coater and the amount of silver used for coating purposes varied by the concentration of the silver precursor (silver nitrate) or the number of silver coatings applied. Potential antimicrobial activity of manufactured silver-coated low-density polyethylene films was tested against Pseudomonas fluorescens, Staphylococcus aureus and microflora isolated from raw chicken. The microbiological and physicochemical quality of chicken breast fillets wrapped with silver-coated low-density polyethylene films followed by vacuum skin packaging was also assessed during storage. Antimicrobial activity of developed silver-coated low-density polyethylene films was dependent ( p 
    Matched MeSH terms: Metal Nanoparticles*
  9. Chan SK, Kuzuya A, Choong YS, Lim TS
    SLAS Discov, 2019 01;24(1):68-76.
    PMID: 30063871 DOI: 10.1177/2472555218791743
    The inherent ability of nucleic acids to recognize a complementary pair has gained wide popularity in DNA sensor applications. DNA molecules can be produced in bulk and easily incorporated with various nanomaterials for sensing applications. More complex designs and sophisticated DNA sensors have been reported over the years to allow DNA detection in a faster, cheaper, and more convenient manner. Here, we report a DNA sensor designed to function like a switch to turn "on" silver nanocluster (AgNC) generation in the presence of a specific DNA target. By defining the probe region sequence, we are able to tune the color of the AgNC generated in direct relation to the different targets. As a proof of concept, we used dengue RNA-dependent RNA polymerase conserved sequences from all four serotypes as targets. This method was able to distinguish each dengue serotype by generating the serotype-respective AgNCs. The DNA switch was also able to identify and amplify the correct target in a mixture of targets with good specificity. This strategy has a detection limit of between 1.5 and 2.0 µM depending on the sequence of AgNC. The DNA switch approach provides an attractive alternative for single-target or multiplex DNA detection.
    Matched MeSH terms: Metal Nanoparticles/chemistry
  10. Gorain B, Tekade M, Kesharwani P, Iyer AK, Kalia K, Tekade RK
    Drug Discov Today, 2017 04;22(4):652-664.
    PMID: 28219742 DOI: 10.1016/j.drudis.2016.12.007
    To avoid tissue rejection during organ transplantation, research has focused on the use of tissue engineering to regenerate required tissues or organs for patients. The biomedical applications of hyperbranched, multivalent, structurally uniform, biocompatible dendrimers in tissue engineering include the mimicking of natural extracellular matrices (ECMs) in the 3D microenvironment. Dendrimers are unimolecular architects that can incorporate a variety of biological and/or chemical substances in a 3D architecture to actively support the scaffold microenvironment during cell growth. Here, we review the use of dendritic delivery systems in tissue engineering. We discuss the available literature, highlighting the 3D architecture and preparation of these nanoscaffolds, and also review challenges to, and advances in, the use dendrimers in tissue engineering. Advances in the manufacturing of dendritic nanoparticles and scaffold architectures have resulted in the successful incorporation of dendritic scaffolds in tissue engineering.
    Matched MeSH terms: Nanoparticles/administration & dosage*
  11. Rohaizu R, Wanrosli WD
    Ultrason Sonochem, 2017 01;34:631-639.
    PMID: 27773290 DOI: 10.1016/j.ultsonch.2016.06.040
    Highly stable and dispersible nanocrystalline cellulose (NCC) was successfully isolated from oil palm empty fruit bunch microcrystalline cellulose (OPEFB-MCC), with yields of 93% via a sono-assisted TEMPO-oxidation and a subsequent sonication process. The sono-assisted treatment has a remarkable effect, resulting in an increase of more than 100% in the carboxylate content and a significant increase of approximately 39% in yield compared with the non-assisted process. TEM images reveal the OPEFB-NCC to have rod-like crystalline morphology with an average length and width of 122 and 6nm, respectively. FTIR and solid-state 13C-NMR analyses suggest that oxidation of cellulose chain hydroxyl groups occurs at C6. XRD analysis shows that OPEFB-NCC consists primarily of a crystalline cellulose I structure. Both XRD and 13C-NMR indicate that the OPEFB-NCC has a lower crystallinity than the OPEFB-MCC starting material. Thermogravimetric analysis illustrates that OPEFB-NCC is less thermally stable than OPEFB-MCC but has a char content of 46% compared with 7% for the latter, which signifies that the carboxylate functionality acts as a flame retardant.
    Matched MeSH terms: Nanoparticles/chemistry*
  12. Jafarzadeh S, Rhim JW, Alias AK, Ariffin F, Mahmud S
    J Sci Food Agric, 2019 Apr;99(6):2716-2725.
    PMID: 30350410 DOI: 10.1002/jsfa.9439
    BACKGROUND: Active food packaging films with improved properties and strong antimicrobial activity were prepared by blending mixed nanomaterials with different ratio [1:4 (40 mg:160 mg), 3:2 (120 mg: 80 mg), 0:5 (0 mg: 200 mg) and 5:0 (200 mg:0 mg)] of ZnO and kaolin with semolina using a solvent casting method and used for the packaging of low moisture mozzarella cheese to test the effect of packaging on the quality change of the cheese for long-term (up to 72 days) refrigerated storage.

    RESULTS: Compared with the neat semolina film, mechanical strength (TS) of the nanocomposite films increased significantly (increase in 21-65%) and water vapor barrier (WVP) and O2 gas barrier (OP) properties decreased significantly (decrease in 43-50% and 60-65%, respectively) depending on the blending ratio of ZnO and kaolin nanoclay. The nanocomposite films also exhibited strong antimicrobial activity against bacteria (E. coli and S. aureus), yeast (C. albicans), and mold (A. niger). The nanocomposite packaging films were effectively prevented the growth of microorganisms (coliforms, total microbial, and fungi) of the cheese during storage at low-temperature and showed microbial growth of less than 2.5 log CFU/g after 72 days of storage compared to the control group, and the quality of the packaged cheese was still acceptable.

    CONCLUSION: The semolina-based nanocomposite films, especially Sem/Z3 K2 film, were effective for packaging of low moisture mozzarella cheese to maintain the physicochemical properties (pH, moisture, and fat content) and quality (color, taste, texture, and overall acceptability) of the cheese as well as preventing microbial growth (coliforms, total microbial, and fungi). © 2018 Society of Chemical Industry.

    Matched MeSH terms: Nanoparticles/chemistry*
  13. Thongprapai P, Cheewasedtham W, Chong KF, Rujiralai T
    J Sep Sci, 2018 Dec;41(23):4348-4354.
    PMID: 30267469 DOI: 10.1002/jssc.201800441
    A magnetic nanographene oxide sorbent as a selective sorbent for the magnetic solid-phase extraction combined with high-performance liquid chromatography and fluorescence detection was developed and proved to be a robust method for zearalenone determination in corn samples. Optimum extraction of zearalenone (20 mg magnetic nanographene oxide sorbent, extraction for 15 min, desorption time of 15 min using 1 mL of 0.5% formic acid in methanol) resulted in low limits of detection (05 mg/L) and quantitation (0.13 mg/L) and good linearity range of 0.13-1.25 mg/L with the correlation coefficient of 0.9957. Acceptable recoveries (79.3-80.6%) with relative standard deviations below 4% and satisfactory intra- and interday precisions (2-7.4%) were achieved. Additionally, the proposed method has been proved to be good in several aspects: easily prepared sorbent with high affinity to zearalenone, convenient and fast procedure, and high extraction efficiency.
    Matched MeSH terms: Magnetite Nanoparticles/chemistry*
  14. Dua K, Madan JR, Chellappan DK, Gupta G
    Panminerva Med, 2018 09;60(3):135-136.
    PMID: 30176702 DOI: 10.23736/S0031-0808.18.03442-0
    Matched MeSH terms: Metal Nanoparticles/chemistry
  15. Sabbagh F, Muhamad II, Nazari Z, Mobini P, Taraghdari SB
    Mater Sci Eng C Mater Biol Appl, 2018 Nov 01;92:20-25.
    PMID: 30184743 DOI: 10.1016/j.msec.2018.06.022
    This study conducted on the structure of modified acrylamide-based hydrogel by synthesizing the nano composites. The hydrogels employed in this study were provided through a combination of acrylamide monomers, sodium carboxymethyl cellulose (NaCMC) and magnesium oxide (MgO) nanoparticles by crosslinking polymerization. N,N,N',N'-tetramethylethylenediamine and ammonium persulfate as the initiator was applied in the structure of the polymer. Findings of the study considered the nano composites consisting of MgO have the highest swelling ratio compared to pure Aam hydrogels. Thus, MgO is an appropriate nanoparticle to be used in the nano composites. Response surface methodology (RSM) based on a central composite design (CCD Design) was applied to optimize the preparation variables of a hydrogel consisted of MgO, NaCMC. With the swelling ratio for acrylamide-based hydrogel as the response, the effects of two variables, i.e. MgO and NaCMC were investigated. The effects of pH, temperature, MgO, and NaCMC on the drug release were investigated using the CCD design. The predicted appropriate drug release conditions for the hydrogel at the highest rate of temperature (37.50 °C) and pH: 4.10, is at its highest value, while the lower drug release is at temperature 38 °C and pH 3.50. With the desired value of MgO (0.01 g) and amount of NaCMC (0.1 g).
    Matched MeSH terms: Nanoparticles/chemistry
  16. Makhadmeh GN, Abdul Aziz A
    Artif Cells Nanomed Biotechnol, 2018;46(sup3):S1043-S1046.
    PMID: 30449196 DOI: 10.1080/21691401.2018.1528982
    BACKGROUND: Achieved Silica Nanoparticles (SiNPs) to encapsulate the photosensitizer [Protoporphyrin IX (PpIX)] in photodynamic therapy (PDT) application was reported in this research.

    MATERIALS AND METHODS: Cytotoxicity for five different concentrations of encapsulated and naked PpIX was measured. Optimum concentration and optimum exposure time of encapsulated and naked PpIX that needed to destroy the cells (Osteosarcoma cells) was measured.

    RESULTS: The results showed that the encapsulated PpIX has more efficacy compared to the naked PpIX and the applicability of the encapsulated PpIX-SiNPs was proved on osteosarcoma cells.

    CONCLUSION: The results established the important in-vitro photodynamic effectiveness of PpIX-SiNP, which may open a new application for PpIX in its clinical and in-vitro studies.

    Matched MeSH terms: Nanoparticles/therapeutic use*
  17. Amin F, Khan S, Shah SMH, Rahim H, Hussain Z, Sohail M, et al.
    Drug Des Devel Ther, 2018;12:3855-3866.
    PMID: 30510401 DOI: 10.2147/DDDT.S183534
    Background: The obnoxious bitter taste of orally taken antibiotics is one of the biggest problems in the treatment of children. The pediatric population cannot tolerate the bitter taste of drugs and vomit out which ultimately leads to suboptimal therapeutic value, grimace and mental stress so it is the challenging task for the formulation scientists to formulate a palatable formulation particularly to overcome address the issue.

    Purpose of study: The study aimed to mask and evaluate the unpleasant bitter taste of azithro-mycin (AZ) in the dry suspension dosage form by physisorption technique.

    Materials and methods: AZ was selected as an adsorbent and titanium dioxide nanoparticles as adsorbate. The AZ nanohybrids (AZN) were prepared by treating fixed amount of adsorbent with a varied amount of adsorbate, prepared separately by dispersing it in an aqueous medium. The mixture was sonicated, stirred followed by filtration and drying. The AZN produced were characterized by various techniques including scanning electron microscopy (SEM), energy dispersive X-rays (EDX), powder X-ray diffraction (PXRD), HPLC and Fourier-transformed infrared (FTIR). The optimized nanohybrid was blended with other excipients to get stable and taste masked dry suspension dosage form.

    Results: The results confirmed the adsorption of titanium dioxide nanoparticles on the surface of AZ. The fabricated optimized formulation was subjected for taste masking by panel testing and accelerated stability studies. The results showed a remarkable improvement in bitter taste masking, inhibiting throat bite without affecting the dissolution rate. The product showed an excellent stability both in dry and reconstituted suspension. The optimized formulation of AZN and was found stable when subjected to physical and chemical stability studies, this is because of short and single step process which interns limits the exposure of the product to various environmental factors that could potentially affect the stability of the product. The dissolution rate of the optimized formulation of AZN was compared with its marketed counterpart, showing the same dissolution rate compared to its marketed formulation.

    Conclusion: The current study concludes that, by fabricating AZ-titanium nanohybrids using physisorption can effectively mask the bitter taste of the drug. The palatability and stability of azithromycin formulation was potentially enhanced without affecting its dissolution rate.

    Matched MeSH terms: Nanoparticles/chemistry*
  18. Tang KS
    Life Sci, 2019 Dec 15;239:117011.
    PMID: 31669241 DOI: 10.1016/j.lfs.2019.117011
    Diabetes mellitus (DM) is a multifaceted and costly disease, which requires serious attention. Finding a cheaper anti-diabetic alternative that can act on multiple disease-related targets and pathways is the ultimate treatment goal for DM. Nanotechnology has offered some exciting possibilities in biomedical and drug delivery applications. Zinc oxide nanoparticles (ZnO-NPs), a novel agent to deliver zinc, have great implications in many disease therapies including DM. This review summarizes the pharmacological mechanisms by which ZnO-NPs alleviate DM and diabetic complications. Research implications and future perspectives were also discussed.
    Matched MeSH terms: Metal Nanoparticles/therapeutic use*
  19. Khalil I, Yehye WA, Muhd Julkapli N, Sina AA, Rahmati S, Basirun WJ, et al.
    Analyst, 2020 Feb 17;145(4):1414-1426.
    PMID: 31845928 DOI: 10.1039/c9an02106j
    Surface enhanced Raman scattering (SERS) DNA biosensing is an ultrasensitive, selective, and rapid detection technique with the ability to produce molecule-specific distinct fingerprint spectra. It supersedes the long amplicon based PCR assays, the fluorescence and spectroscopic techniques with their quenching and narrow spectral bandwidth, and the electrochemical detection techniques using multiplexing. However, the performance of the SERS DNA biosensor relies on the DNA probe length, platform composition, both the presence and position of Raman tags and the chosen sensing strategy. In this context, we herein report a SERS biosensor based on dual nanoplatforms with a uniquely designed Raman tag (ATTO Rho6G) intercalated short-length DNA probe for the sensitive detection of the pig species Sus scrofa. In the design of the signal probe (SP), a Raman tag was incorporated adjacent to the spacer arm, followed by a terminal thiol modifier, which consequently had a strong influence on the SERS signal enhancement. The detection strategy involves the probe-target DNA hybridization mediated coupling of the two platforms, i.e., the graphene oxide-gold nanorod (GO-AuNR) functionalized capture probe (CP) and SP-conjugated gold nanoparticles (AuNPs), consequently enhancing the SERS intensity by both the electromagnetic hot spots generated at the junctions or interstices of the two platforms and the chemical enhancement between the AuNPs and the adsorbed intercalated Raman tag. This dual platform based SERS DNA biosensor exhibited outstanding sensitivity in detecting pork DNA with a limit of detection (LOD) of 100 aM validated with DNA extracted from a pork sample (LOD 1 fM). Moreover, the fabricated SERS biosensor showed outstanding selectivity and specificity for differentiating the DNA sequences of six closely related non-target species from the target DNA sequences with single and three nucleotide base-mismatches. Therefore, the developed short-length DNA linked dual platform based SERS biosensor could replace the less sensitive traditional methods of pork DNA detection and be adopted as a universal detection approach for the qualitative and quantitative detection of DNA from any source.
    Matched MeSH terms: Metal Nanoparticles/chemistry
  20. Syamila N, Syahir A, Ikeno S, Tan WS, Ahmad H, Ahmad Tajudin A
    Colloids Surf B Biointerfaces, 2020 Jan 01;185:110623.
    PMID: 31735420 DOI: 10.1016/j.colsurfb.2019.110623
    Bio-nanogate involves synthesized or natural molecules as a 'gate' towards bioreceptors and responds upon the presence of targeted analytes in nanoscale dimension. Development of bio-nanogate improves analyte selectivity and signal response across various types of biosensors. The versatility of PAMAM dendrimers to form conjugates with guest molecules, such as proteins can be utilized in forming a bio-nanogate. PAMAM interaction with peptide bioreceptor for antibody detection is of interest in this study. This study investigated the interaction of synthesized immunogenic 'a' determinant (aD) region of hepatitis B virus surface antigen (HBsAg) with PAMAM G4 and anti-HBsAg antibody, as a potential bio-nanogate for anti-HBsAg detection. The aD peptide fused with maltose binding protein (MBP), was confirmed with Western blotting. Nano-Differential Scanning Fluorimetry (nano-DSF) study revealed that the interaction of MBP-aD with anti-HBsAg indicated a higher thermal stability as compared to its interaction with PAMAM G4. Electrochemical impedance spectroscopy showed that a higher binding constant of MBP-aD interaction with anti-HBsAg (0.92 μM-1) was observed at maximum saturation, as compared with PAMAM G4 (0.07 μM-1). Thermodynamic parameters demonstrated that MBP-aD interacted with anti-HBsAg and PAMAM G4, through van der Waals and hydrogen bonding. These analyses suggest that the weak interaction of MBP-aD and PAMAM G4 may form a potential bio-nanogate. It is hypothesized that the presence of anti-HBsAg has a higher affinity towards MBP-aD which may displace PAMAM G4 in the anti-HBsAg detection system. This interaction study is crucial as an initial platform of using peptide-PAMAM as a bio-nanogate in an antibody detection system.
    Matched MeSH terms: Nanoparticles/chemistry*
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