Abstract
Bisphenol A (BPA) is a toxic chemical used by industries for production of containers for storage of food and beverages leading to possible health risks. In this work, we present a simple, mask-free, low-cost imprinted sensor based on laser scribed graphene (LSG) technology combined to molecularly imprinted polymers (MIPs) for BPA determination. CO2 laser was used in production of LSG electrodes with high conductivity and multilayer structure by using less laser speed/power (2.8 cm/s/3.2 W) and low resistivity 58 Omega/square on flexible polyimide sheet leading to the high active surface area of the sensor. LSG device was functionalized with imprinted polypyrrole with a known amount of BPA as template molecule to develop the sensor. The bare LSG, LSG-MIP, LSG-NIP sensors were characterized using Raman spectroscopy, SEM, XRD, AFM. The electrochemical measurements were carried out using cyclic voltammetry and differential pulse voltammetry. Experimental conditions were optimized, including the concentration of pyrrole monomer, the number of polymerization cycles, the concentration of BPA as template and the incubation time. We evaluated the sensitivity of the LSG-MIP sensor in the concentration range between 0.05 mu M and 20 mu M with a limit of detection of 8 nM. The proposed sensor exhibits high selectivity towards BPA compared to its structural analogs and good reusability. The developed sensor was successfully applied for the detection of BPA in tap, mineral water and in plastic samples. The developed sensor was integrated into a PMMA case connected to the potentiostat to achieve complete isolation and a practical measurement system.