Fluorescent carbon dots (CDs) have become a potent and adaptable nanomaterial in recent years for the sensitive and specific detection of heavy metal ions. Ferric ion (Fe3+) is one of the most damaging metal ions that can infiltrate the human body and the environment. In this study, blue-emitting carbon dots (CDs) were successfully synthesized from lemon juice using a hydrothermal process. The sensitivity of CDs to Fe3+ ions was examined using various concentrations of Fe3+ (0-400 µM) under different pH conditions (3, 5, 7, 9, 11, and 13) by measuring UV-Vis absorbance at 200-700 nm. The findings showed that the interaction between CDs and Fe3+ is significantly influenced by pH, resulting in varying absorbance enhancement responses. To get more profound insights into this pH-dependent performance, multivariate analysis techniques, including principal component analysis (PCA), linear discriminant analysis (LDA), and partial least squares regression (PLSR) were utilized. By combining these techniques with experimental data, significant correlations between pH levels, π - π ∗ and n - π ∗ electronic transitions of CDs, and Fe3⁺ sensing performance were identified. According to the PLSR model, pH 7 is ideal for real-world uses since it offers the optimum balance between Fe3⁺ solubility and CDs sensing capabilities, closely matching environmental and physiological conditions. This work contributes to the knowledge of CDs-based sensing mechanisms and emphasizes the value of multivariate analysis in boosting material performance for real-world applications in the biochemical and environmental domains.
The transition to electric vehicles (EVs) calls for sustainable advancements in automotive lubricants, as traditional fossil-fuel-based products pose environmental challenges. Palm oil-based biolubricants enriched with nanoparticles present a promising eco-friendly alternative that meets the thermal and tribological demands of EVs. This paper aims to analyze the development of nanoparticle-enriched palm oil-based biolubricants, aimed at improving the sustainability and performance of electric vehicle (EV) lubrication systems. The critical findings highlight that integrating nanoparticles such as graphene, titanium dioxide, and aluminum oxide into palm oil-based lubricants significantly enhances their tribological properties. These enhancements include a 26.21%-34% reduction in coefficient of friction (COF), a 12.99%-30% reduction in wear, and improved thermal stability. The study found that nanoparticle-enriched biolubricants outperformed traditional options in terms of friction and wear under high-temperature and pressure conditions, as supported by regression analysis. The study demonstrates that nanoparticle-enriched biolubricants offer a viable eco-friendly alternative to conventional lubricants, lowering the environmental impact by reducing greenhouse gas emissions and energy consumption. This innovation has significant implications for both the environment and industry, offering a sustainable solution that reduces dependency on fossil fuels, enhances EV efficiency, and aligns with global sustainability goals. Besides, this paper discusses biolubricants drawbacks and future studies direction.