ABSTRACT
In this paper a simple electrochemical sensing of dopamine by a new effective immobilization of tyrosinase (Tyr) enzyme on eggshell membrane (ESM) along with silver nanoparticles (AgNPs) is reported. The modified membrane was characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDAX), X-Ray diffraction (XRD). A simple solution based approach was used to prepare AgNPs on biomembrane followed by glutaraldehyde activation to immobilize Tyr on the nanoparticles decorated ESM. The direct electrochemistry of DA oxidation was performed through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Characterization of membrane was accomplished by electrochemical impedance spectroscopy (EIS). Prepared electrode showed very good stability, reproducibility, high selectivity, easy preparation and regeneration of electrode. The proposed sensor exhibited low detection limits 1.7ngL−1 with wide linear range 10–1000 ngL−1, excellent sensitivity (14.28µA µgL−1cm−2) with good storage and operational stabilities. The accurate measurement of dopamine in blood serum and good recoveries in spiked serum samples ensured great potential for medical diagnostics.
Acknowledgment
The author (SD) is indebted to CSIR, New Delhi for her fellowship. The authors acknowledge Mr. Pratyush of Centre for nanoscience and nanotechnology (CRNN), University of Calcutta, for providing assistance in characterization of nanoparticles and biopolymer.