A scalable electrochromic aptasensing interface as a highly selective Apta-Chip for visual detection of methamphetamine

چکیده مقاله

Background: Methamphetamine (MAMP) is an arousing addictive drug and its close tracing in human biofluids or suspected shipments to diagnose poisoning or aid in its induced death investigation is legally important. This study presents a rapid and visual measurement of MAMP based on a novel platform involving the electrochromic properties of polyaniline (PANI). PANI film has been electrochemically deposited on the surface of indium tin oxide (ITO) to achieve the desired electrochromic behavior and also embed a suitable platform for the attachment of the aptamer (Apt) as the bioreceptor for MAMP with high affinity. Results: For the first time, an electrochromic aptasensing interface, referred to as the Apta-Chip, has been created by combining two electrochemical and optical methods for measuring MAMP. The developed Apta-Chip based on the PANI/ITO surface displays a wide range of colors at close potentials, serving as an electrochromic optical detector. The presence of MAMP on the embedded surface increases the resistance in the circuit, affecting the PANI oxidation states, creating a different electrochromic response that depends on MAMP concentration. Thereby, the optical detection of MAMP is performed with the naked eye, yielding highly favorable outcomes for MAMP monitoring in human serum, urine and saliva samples, as biofluid samples. Compared to conventional MAMP sensors, the proposed Apta-Chip provides a multicolor behavior with vivid tonality from dark blue, green and dark yellow for different MAMP concentrations. Significance: The molecular dynamics (MD) simulation has been carried out to predict how Apt links to MAMP visually. Additionally, the greenness of the applied methodology has been well evaluated by two international criteria based on the green chemistry principles. The developed Apta-Chip holds promise to reasonably distinguish MAMP with the naked eye in real clinical or street narcotic samples. © 2025 Elsevier B.V.