Development of an electrochemical sensor based on porous molecularly imprinted polymer via photopolymerization for detection of somatostatin in pharmaceuticals and human serum

This study applied a new methodology to create a porous molecularly imprinted material for the highly selective and sensitive recognition of somatostatin (SOM), a growth hormone inhibitör. N-methacryloyl-l-aspartic acid (MAAsp) was synthesized and used as a functional monomer to form a molecularly imprinted polymer (MIP) by photopolymerization method on a glassy carbon electrode (GCE). The MIP film was synthesized in the presence of 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) to form P(HEMA-MAAsp)@MIP/GCE sensor. The characterization of P(HEMA-MAAsp)@MIP/GCE was investigated by Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and Electrochemical Impedance Spectroscopy (EIS) techniques. Afterward, the porous P(HEMA-MAAsp)@MIP/GCE was optimized with removal agent, removal time, and incubation time to achieve a better response for SOM. Under optimum conditions, the calibration curve of SOM on the P(HEMA-MAAsp)@MIP/GCE sensor was linear in the range of 10 fM and 100 fM. The limit of detection (LOD) and lower limit of quantification (LLOQ) were found as 0.175 fM and 0.584 fM, respectively. The analytical performance of the P(HEMA-MAAsp)@MIP/GCE sensor was investigated by comparing the electrochemical reaction of MIP with non-imprinted polymer (NIP). The analytical performance of the developed sensor was proved by applying it to the pharmaceutical preparation and serum. The selectivity of the sensor was shown by examining the binding of Octreotide and Lanreotide, which are the synthetic analogs of the SOM. The developed P(HEMA-MAAsp)@MIP/GCE sensor, which is green and sustainable, exhibited high sensitivity and selectivity for SOM and is the first method reported to be used in the electroanalysis of SOM.