ELECTROCHEMICAL IMMUNOSENSOR FOR CYTOKERATIN FRAGMENT-21-1 DETECTION

摘要

The present invention provides in situ synthesis of amino acid (L-Cysteine) capped lanthanum hydroxide nanoparticles [Cys-La(OH)3 NPs] for the fabrication of efficient immunosensor for cytokeratin fragment-21-1 (Cyfra-21-1) biomarker detection. The characterization of Cys-La(OH)3 NPs is carried out by different techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, fourier transform infrared spectroscopy and electrochemical techniques (differential pulse voltammetry). A thin film of Cys-La(OH)3 NPs are electrophoretically deposited onto an indium-tin-oxide glass substrate and used for immobilization of anti-cytokeratin fragment-21-1 (anti-Cyfra-21-1) for the electrochemical detection of Cyfra-21-1 (Scheme). This immunosensor shows a broad detection range of 0.001-10.2 ng mL-1, the low detection limit of 0.012 ng (mL cm-2)-1, and high sensitivity of 12.044 µA (ng per mL cm-2)-1 with a response time of 5 min. This immunosensor is more advanced regarding the high sensitivity and low detection limit.