A kind of new type photoresponsive molecularly imprinted electrochemical sensor based on 5-[(4-(methacryloyloxy)phenyl)diazenyla]isophthalic acid for the detection of carbaryl

As a widely used carbamate pesticide, carbaryl not only had neurotoxicity by inhibiting the activity of acetylcholinesterase, but also had environmental hormone effects, so it is important to establish a convenient and sensitive method for the detection of carbaryl. An original photoresponsive molecularly imprinted electrochemical sensor (MIP-MGCE) was fabricated from glassy carbon electrode (GCE) as the substrate, 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid (MAPDIA) as the functional monomer and carbaryl as the template, where a layer of molecular imprinting film was constructed and overattached on the surface of GCE modified by carboxylic multi-walled carbon nanotube-chitosan (MWCNT-CT) composite with the large specific surface area and good conductivity. The constructed sensors were characterized by FT-IR and cyclic voltammetry (CV). The ratio of template molecule to monomer, elution time, and incubation time were optimized to be 1:4, 2 min and 6 min, respectively. By the differential pulse voltammetry (DPV) method, the experimental amperometric curve of MIP-MGCE had favorable linear relationship. The linear equation was Δ I = 190.2933C + 1.9824 with R 2 = 0.9865 when in the carbaryl concentration range of 0.0035–0.1100 μmol L −1 , and the linear equation became Δ I = 2.8940C + 25.4230 with R 2 = 0.9917 when in the range of 0.1100–13.9600 μmol L −1 . The detection limit of the above method was 0.0011 μmol L −1 ( S / N = 3). The prepared sensor was also applied to the detection of carbaryl in tap water samples, and the results showed it had not only a better recovery rate of 97.00% with 3.43% of RSD but also excellent selectivity and repeatability. Graphical abstract