Fabrication of Molecularly Imprinted Electrochemical Sensor for Selective Detection of Propranolol Hydrochloride

Carbon dot-based molecularly imprinted polymer fluorescent sensor for the detection of propranolol in plasma

Propranolol, a medication used to treat cardiovascular diseases, can be harmful when overdosed and hazardous to ecosystems if released into the environment. Here, a new molecularly imprinted fluorescent sensor was developed from carbon dots through a sol-gel method. Carbon dots served as both the fluorescent signal and the carrier, with propranolol as the template molecule and 3-aminopropyltriethoxysilane as the functional monomer to be grafted on carbon dots' surface. A novel detection method was established for the efficient, rapid, and cost-effective detection of propranolol in human plasma through quantitative analysis by using a fluorescence spectrophotometer and an ultraviolet spectrophotometer. Under the optimal conditions, the detection range of 0.5-4 mg L-1, the detection limit of 0.092 mg L-1, the imprinting factor of 2.42, and the detection response time of 2 min were achieved. The prepared carbon dot-based molecularly imprinted fluorescent sensor was proved to have a wide accurate linear range, low detection limit, and very short response time, and can detect lower analyte concentrations with higher detection accuracy.

Recognition of protein biomarkers using epitope-mediated molecularly imprinted films: Histidine or cysteine modified epitopes?

This research aims to engineer molecularly imprinted polymer (MIP)-based synthetic receptors for the molecular recognition of neuron specific enolase (NSE) biomarker. The synthetic peptide derived from the NSE was synthesized along with its cysteine and histidine modified versions. The modified peptides were utilized as templates for molecular imprinting, which was achieved by combination of epitope- and electrochemical surface imprinting strategy. The subsequently generated imprinted cavities were used for the detection of the NSE derived peptide and NSE. The imprints created with cysteine (CME) and histidine modified epitopes (HME) could detect the peptide in a concentration range of 2-128 µM and 15.6 nM to 128 µM, respectively. The recognition of NSE was achieved by the same imprints in a linear range of 1-64 ng mL^-1 (CME) and 0.25-64 ng mL^-1 (HME), respectively. The target molecules bound to the control polymer very weakly, confirming the high selectivity of the MIP cavities. Selectivity studies resulted in imprinting factors of 8.8 and 11 for the CME and HME imprints, respectively. The affinity analyses provided dissociation constants of 2.3 × 10^-10 M and 3 × 10^-11 M for NSE recognition using the corresponding epitope imprints. Cross-reactivity studies with non-specific molecules proved high specificity of the artificial receptors for the targets.