An MWCNT-based dummy-template molecularly imprinted electrochemical sensor for detecting 2-methylisoborneol in water.

The typical off-flavor compound 2-methylisoborneol (2-MIB) is widely present in water bodies which induces unpleasant odors in water even at extremely low concentrations. It is urgent to develop a simplified laboratory-based electrochemical screening workflow for trace 2-MIB quantification since the traditional detection techniques are time-consuming and require complex pretreatment procedures. This study developed an innovative molecularly imprinted electrochemical sensor by using multi-walled carbon nanotubes (MWCNTs), molecularly imprinted polymers (MIPs), and a glassy carbon electrode (GCE) to detect trace 2-MIB in water. The sensor enabled highly specific capture of 2-MIB relying on the distinctive recognition cavities of MIPs. The theoretical saturated adsorption capacity extrapolated via the Langmuir model was calculated to be 6742 μg g-1. Systematic optimization was performed to achieve the best detection performance. The sensor exhibited a good linear response toward 2-MIB in the range of 25-200 ng L-1 under optimal conditions with a regression equation of ΔI (μA) = 0.34C + 2.1 and a correlation coefficient R2 = 0.9972. The method detection limit for 2-MIB reached 1.6 ng L-1, providing a screening strategy for trace 2-MIB in environmental water samples. The MWCNTs@DMIPs/GCE sensor showed good selectivity, reproducibility, and stability with satisfactory recoveries of 2-MIB ranging from 92.1% to 100.4% in different water samples. These findings of this study provide a feasible electrochemical screening technique for trace off-flavor substance detection.