Rapid and Sensitive Detection of Sulfamethizole Using a Reusable Molecularly Imprinted Electrochemical Sensor

Abstract

Efficient methods for monitoring sulfonamides (SAs) in water and animal-source foods are of great importance to achieve environmental safety and protect human health. Here, we demonstrate a reusable and label-free electrochemical sensor for the rapid and sensitive detection of sulfamethizole based on an electropolymerized molecularly imprinted polymer (MIP) film as the recognition layer. To achieve effective recognition, monomer screening among four kinds of 3-substituted thiophenes was performed by computational simulation and subsequent experimental evaluation, and 3-thiopheneethanol was finally selected. MIP synthesis is very fast and green, and can be in situ fabricated on the transducer surface within 30 min in an aqueous solution. The preparation process of the MIP was characterized by electrochemical techniques. Various parameters affecting MIP fabrication and its recognition response were investigated in detail. Under optimized experimental conditions, good linearity in the range of 0.001−10 μM and a low determination limit of 0.18 nM were achieved for sulfamethizole. The sensor showed excellent selectivity, which can distinguish between structurally similar SAs. In addition, the sensor displayed good reusability and stability. Even after 7 days of storage, or being reused 7 times, higher than 90% of the initial determination signals were retained. The practical applicability of the sensor was also demonstrated in spiked water and milk samples at the nM determination level with satisfactory recoveries. Compared to relevant methods for SAs, this sensor is more convenient, rapid, economical, and eco-friendly, and had comparable or even higher sensitivity, which offered a simple and efficient method for SA detection.

Recent Advances in Conductive Polymers-Based Electrochemical Sensors for Biomedical and Environmental Applications

“…The excessive use and improper disposal of antibiotics, as well as the discharge of animal and human waste, aquaculture practices, hospital and industrial waste, along with inefficient removal during conventional water treatment processes contribute to the build-up of antibiotics in both food and the environment. Consequently, antibiotics have been identified as an emerging environmental pollutant in recent years [ 154 , 155 , 156 ].…”

“…Due to their high efficacy and cost-effectiveness, SAs have been extensively utilized for the prevention and control of human and animal infections as well as for promoting animal husbandry growth [ 159 ]. Kong’s group demonstrated a reusable and label-free electrochemical sensor utilizing an electropolymeric MIP film as an identification layer for rapid and sensitive detection of sulfamethozole [ 155 ]. In order to achieve effective identification, computational simulation and subsequent experimental evaluation were conducted for monomer screening of four 3-substituted thiophenes, ultimately selecting 3-thiophene ethanol.…”