A "Single-Use" Ceramic-Based Electrochemical Sensor Chip Using Molecularly Imprinted Carbon Paste Electrode

An inexpensive disposable electrochemical drug sensor for the detection of drugs (vancomycin, meropenem, theophylline, and phenobarbital) is described. Molecularly imprinted polymer (MIP) templated with the target drugs was immobilized on the surface of graphite particles using a simple radical polymerization method and packed into the working electrode of a three-electrode ceramic-based chip sensor. Differential pulse voltammetry (DPV) was used to determine the relationship between the response current and the concentration of the targeted drug while using one sensor chip for one single operation. The time required for each DPV measurement was less than 2 min. Concentrations corresponding to the therapeutic range of these drugs in plasma were taken into account while performing DPV. In all the cases, the single-used MIP sensor showed higher sensitivity and linearity than non-imprinted polymer. The selectivity test in drugs with a structure similar to that of the target drugs was performed, and it was found that MIP-based sensors were more selective than the untreated ones. Additionally, the test in whole blood showed that the presence of interfering species had an insignificant effect on the diagnostic responses of the sensor. These results demonstrate that the disposable MIP-sensor is promising for quick and straightforward therapeutic drug monitoring to prevent the toxic side effects and the insufficient therapeutic effect due to the overdose and underdose, respectively.