Advances in functionalized nanoparticle biosensor arrays for substance abuse diagnostics: A review of Green Synthesis, Biorecognition, and Clinical Integration

Challenges associated with substance dependence will likely be an issue for years to come. It affects unfavorably the socioeconomics concerning healthcare and public safety each and every community, and the world. As of 2021, the WHO states that 296 million people used illicit drugs, and that each year, opioid use results in over 125,000 deaths. Diagnostic techniques are primarily based on chromatographic approaches, namely, gas and liquid chromatography-mass spectrometry and enzyme-linked immunosorbent assays. These approaches are limited in their use for diagnostic techniques at the point-of-care due to the need for an advanced laboratory setup, lengthy periods for test results, and high operational costs. These factors greatly affect clinical decisions in a timely manner during emergencies that require fast identification of a substance to provide the correct treatment. Latest developments in biosensor technology show great potential in some diagnostic biosensor applications. There is a significant biosensor focus on the competitive advantages provided by biosensors integrating biosensors incorporating green synthesized nanomaterials in terms of biocompatibility, environmental sustainability, and cost in comparison to chemical synthesis. The most recent advances in point of care functionalized, core-shell architecture, nanoparticle arrays have simplified the operational requirements while achieving a new operational level of sensitivity and specificity for point of care diagnostics. Among these technological advances, the patented gold-cerium oxide core-shell biosensor system developed represents an important milestone in green nano biosensor invention, combining plant-extract-mediated nanoparticle synthesis with multiplexed electrochemical detection capabilities. Furthermore, this review evaluates the biomedical implications of these technologies, including their potential to democratize access to reliable substance testing in resource-limited settings, enhance workplace safety protocols, support forensic investigations, and facilitate personalized addiction treatment monitoring. Keywords: Functionalized Nanoparticles, Biosensor Arrays, Substance Abuse Diagnostics, Green Synthesis, Gold-Cerium Oxide Core-Shell, Biorecognition Elements, Electrochemical Detection, Point-Of-Care Testing, Nanobiotechnology, Clinical Integration.