Synthesis of nano-sized timolol-imprinted polymer via ultrasonication assisted suspension polymerization in silicon oil and its use for the fabrication of timolol voltammetric sensor

摘要

A novel timolol voltammetric sensor based on the nano-sized molecularly imprinted polymer (nano-MIP)-mod-ified carbon paste electrode was introduced. Timolol-imprinted polymers (MIP) were synthesized by the ultrasonic assisted suspension polymerization in silicon oil. The MIP nanoparticles were then embedded in a carbon paste (CP) electrode in order to prepare the nano-MIP-CP electrode. Timolol was extracted in the electrode for a definite time and then it was analyzed by square wave voltammetry, found to be an effective determination method. The electrode showed higher response to timolol, compared to the CP electrode, and CP electrode modified with non-imprinted polymer (nano-NIP-CP). Various factors, known to affect the response behavior of the nano-MIP-CP electrode, were investigated and optimized. The sensor exhibited distinct linear response ranges of 1.0 x 10~(-7)-2.1 x 10~(-6) M with the sensitivity of 71.523 µAµM~(-1).The lower detection limit of the sensor was calculated to be 23 x 10~(-8) M (S/N = 3). The sensor was applied successfully for timolol determination in pharmaceutical formulations, blood serum and urine samples.