Electrochemical immunosensor for the prostate specific antigen detection based on carbon nanotube and gold nanoparticle amplification strategy

Abstract

We describe a highly sensitive electrochemical sandwich-type immunosensor for the prostate specific antigen (PSA), a biomarker related to prostate cancer. A glassy carbon electrode was covalently modified with multiwalled carbon nanotubes to which the anti-PSA was immobilized. Following addition of a sample containing PSA, a secondary antibody is added that consists of gold nanoparticles modified with secondary antibody and 6-ferrocenyl hexanethiol acting as the signal molecule. This approach represents a multiple signal amplification strategy in that the functionalized carbon nanotubes improve the electron transfer on the surface of the electrode, while the gold nanoparticles act as carriers for capturing large quantities of Ab 2 and ferrocene. The modifying processes were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimal conditions, the differential pulse voltammetric signals (acquired at a typical potential of 0.31 V vs. SCE) is linearly related to the concentration of PSA in the 10 pg.mL −1 to 100 ng.mL −1 range. The detection limit is 5.4 pg.mL −1 . When applied to the determination of PSA in spiked human serum, the recoveries were between 92.4 and 120.0 %. We perceive that this immunosensor holds great promise in the field of clinical screening for cancer biomarkers.

Non-enzymatic electrochemical immunoassay using noble metal nanoparticles: a review

“…Generally, they combined with noble metal nanoparticles through covalent linkage or electrostatic interaction, which directly produce on quantitive electrochemical signals. Wang's group describe a sensitive electrochemical sandwich-type immunosensor for the determination of prostate specific antigen (PSA) based on 6-ferrocenyl hexanethiol (Fc) modified gold nanoparticles as signal labels [57]. The immunosensor exhibited ideal performance for the detection of PSA.…”

Recent Advances in Enhancement Strategies for Electrochemical ELISA-Based Immunoassays for Cancer Biomarker Detection

“…Yang et al described the use of 6-ferrocenyl hexanethiol tagged AuNPs based probe development for PSA detection. With high physical loading of anti-PSA onto Fc tagged AuNPs, they were able to detect PSA down to 5.4 pg/mL [ 68 ]. Lin et al introduced the use of AuNPs-mesoporous carbon form (MCF) as redox tag.…”

Electrochemical Biosensing in Cancer Diagnostics and Follow‐up

“…Glutaraldehyde (GA), 1‐pyrenebutanoic acid succinimidyl ester (PBSE), phthaloyl chloride and iminithiolane can also be used. Many immunosensors were described in which carbodiimide chemistry was employed for antibody immobilization , , . In general, in this process the primary amine groups of the antibody are covalently bound to the carboxylic acid group present on the sensor surface, through reactive succinimide esters by amine coupling through EDC/NHS chemistry.…”