Electrochemiluminescence of peroxydisulfate enhanced by l-cysteine film for sensitive immunoassay

• Published in: Biosensors & bioelectronics Vol. 26; no. 7; pp. 3175 - 3180
• Main Authors: Niu, Huan, Yuan, Ruo, Chai, Yaqin, Mao, Li, Yuan, Yali, Zhuo, Ying, Yuan, Shirong, Yang, Xia
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.03.2011; Elsevier
• Subjects: Biological and medical sciences; Biosensors; Biotechnology; Cysteine - chemistry; Electrochemiluminescence; Electrochemistry - methods; Fundamental and applied biological sciences. Psychology; Humans; Immunoassay - methods; Immunosensor; l-Cysteine; Luminescent Measurements - methods; Methods. Procedures. Technologies; Peroxydisulfate solution; Potassium Compounds - chemistry; Receptors, Cytoplasmic and Nuclear - analysis; Receptors, Cytoplasmic and Nuclear - blood; Sensitivity and Specificity; Sulfates - chemistry; Various methods and equipments; α-1-Fetoprotein; l-Cysteine; Electrochemiluminescence; α-1-Fetoprotein; Immunosensor; Peroxydisulfate solution; Cysteine; Biosensor; L-Cysteine; α-Fetoprotein; Immunological method
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2010.12.023

A novel label free electrochemiluminescence (ECL) immunosensor based on the ECL of peroxydisulfate solution for detection of α-1-fetoprotein (AFP) has been developed. For this proposed immunosensor, l-cysteine was firstly electrodeposited on the gold electrode surface, which promoted the electron transfer and largely enhanced the ECL of peroxydisulfate solution. Subsequently, gold nanoparticles (nano-Au) were assembled onto the l-cysteine film modified electrode to improve the absorption capacity of antibody and further amplify the ECL signal. Then, antibody was immobilized onto the electrode through nano-Au. At last bovine serum albumin (BSA) was employed to block the nonspecific binding sites. As a result, a novel ECL immunosensor was firstly obtained by applying the ECL of peroxydisulfate solution without conventional luminescent reagents. The AFP was determined in the range of 0.01–100 ng mL −1, with a low detection limit of 3.3 pg mL −1 (S/N = 3). The proposed ECL immunosensor provides a rapid, simple, and sensitive immunoassay protocol for protein detection, which might hold a promise for clinical application. Moreover, this work would open up a new field in the application of peroxydisulfate solution ECL for highly sensitive bioassays.