Eco-friendly high-performance aptasensor for ultra-sensitive methamphetamine detection in biofluids using carbon felt...

The sensitive and selective detection of narcotics remains a critical challenge due to their health risks and societal impacts. In this study, we developed a high-performance aptasensor for methamphetamine (METH) detection by modifying a carbon felt electrode (CFE) with a nanocomposite of Ti₃C₂T_x MXene and electrochemically deposited silver nanodendrites (AgNDs). The prepared AgNDs/Ti₃C₂T_x/CFE platform exhibited enhanced surface area and electron transfer properties, providing an ideal interface for aptamer (Apt) immobilization. Subsequently, the final aptasensor was fabricated by immobilizing Apt strands on the surface, followed by blocking nonspecific binding sites with bovine serum albumin (BSA). The label-free aptasensor demonstrated excellent analytical performance with two linear detection ranges (10-100 pM and 1-500 nM) and a low detection limit of 3 pM. It also showed high selectivity in the presence of potential interferents and successfully quantified METH in complex human biofluids, including serum, urine, and saliva. Molecular dynamics simulations confirmed the stability of the Apt-METH (ZIN) complex, revealing persistent interactions, site-specific hydrogen bonding, and conformational compaction, affirming the aptamer's binding efficiency. Furthermore, the environmental sustainability of the fabrication strategy was evaluated using green analytical chemistry metrics. The method yielded a high AGREE score of 0.83 and a favorable ComplexGAPI visualization, indicating strong compliance with green chemistry principles. These results underscore the sensor's potential as a reliable, sensitive, scalable, and eco-friendly platform for forensic and clinical narcotics analysis.