Electrochemiluminescence of peroxydisulfate enhanced by L-cysteine film for sensitive immunoassay.
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.
Key Laboratory of Eco-environments in Three Gorges Reservoir Region, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, PR China.
Huan
H
Niu
Ruo
R
Yuan
Yaqin
Y
Chai
Li
L
Mao
Yali
Y
Yuan
Ying
Y
Zhuo
Shirong
S
Yuan
Xia
X
Yang
D003545:Cysteine / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D017680:Potassium Compounds / Q000737:chemistry*; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000097:blood*; D012680:Sensitivity and Specificity; D013431:Sulfates / Q000737:chemistry*
C082631:NR5A2 protein, human; D017680:Potassium Compounds; D018160:Receptors, Cytoplasmic and Nuclear; D013431:Sulfates; C009007:potassium persulfate; D003545:Cysteine