Kamyar Pourghazi - Department of Chemistry, Kharazmi University, Tehran, Iran
Majid Amoli Diva - School of Dentistry, Babol University of Medical Sciences, Babol, Iran
Mahsa Shahmirzadi - Research and Development Department, Darou Pakhsh Pharmaceutical Mfg. Co, Tehran, Iran

Objective(s): Today, there is an urgent need for improved sensor materials for drug sensing and effective monitoring and interventions in this area are highly required to struggle drug abuse. The present study aimed to synthesize a thioguanine-responsive sensor based on a nanocomposite consisting of AuNP-grafted light- and temperature-responsive poly butylmethacrylate-co-acrylamide-co-methacrylic acid ([P(BMA-co-AAm-co-MAA)] with an On/Off switching property in the presence and absence of light radiation.Materials and Methods: The incorporation of AuNPs into the structure of a polymer as the sensing moiety allows the detection of thiol-containing drug based on established gold-sulfur chemistry. The prepared nanocomposite sensor was characterized using transmission electron microscopy, scanning electron microscopy, and Fourier-transform infrared spectroscopy. In addition, the thermal sensitivity and thermal and optical switching properties of the nanocomposite were investigated. The sensor could be triggered by laser radiation at the wavelengths matched with the surface plasmon resonance (SPR) frequency of the AuNPs, providing it with an On/Off switching property.Results: The sensor was observed to have high binding ability indicating its promising sensing applications with the wide linear responsive range of 20-250 µM and low limit of detection (0.1 µM) toward thioguanine.Conclusion: The prepared sensor could be used to detect the analyte in biological and pharmaceutical samples, while it is also efficient in the detection of thioguanine in actual samples.

Au nanoparticles, Dual responsive nanocomposite, Laser, Optical sensor, Thioguanine