Electrochemical prostate specific antigen aptasensor based on hemin functionalized graphene-conjugated palladium nanocomposites

Abstract

An electrochemical aptasensor is described for the detection of prostate specific antigen (PSA). The aptasensor is based on the use of hemin-functionalized graphene-conjugated palladium nanoparticles (H-Gr/PdNPs) deposited on a glassy carbon electrode. The nanocomposites integrate the high electrical conductivity of graphene with the easily functionalized surface chemistry of PdNPs and their excellent catalytic property. The hemin placed on graphene acts as both a protective agent and an in-situ redox probe. The PdNPs provide numerous binding sites for the immobilization of DNA-biotin via coordinative binding between Pd and amino groups. A sensitive and specific PSA assay was attained by immobilizing the PSA aptamer via biotin-streptavidin interaction. The resulting aptasensor has a linear response that covers the PSA concentration range from 0.025 to 205 ng·mL, with a 8 pg·mL lower detection limit (at -0.362 V, scan rate: 0.1 mV·s, S/N = 3). The method was applied to the quantitation of PSA in spiked serum samples, giving recoveries ranging from 95.0 to 100.3%. Graphical abstract A signal amplified and approving electrochemical aptasensor was constructed for the determination of prostate specific antigen (PSA) based on the use of hemin-functionalized graphene conjugated to palladium nanoparticles (H-Gr/PdNPs). The sensor has a wide linear range, a relatively low detection limit, satisfying stability and high specificity.

Design Strategies for Electrochemical Aptasensors for Cancer Diagnostic Devices

“…PdNPs provided numerous binding sites for immobilisation of biotinylated DNA via coordinative binding between Pd and amino groups of DNA’s bases. The PSA aptamer was immobilised via biotin-streptavidin interactions [ 200 ].…”

From Small Molecules toward Whole Cells Detection: Application of Electrochemical Aptasensors in Modern Medical Diagnostics

“…The current signal increased as the electron transfer was enhanced, and a linear response was recorded in the range from 0.025 to 204.8 µg·L −1 with a lower limit of detection of 8 ng·L −1 . The current signal did not change after electrode incubation with interfering molecules, including thrombin, intravenous gamma globulin (IgG), HSA, and CEA [ 126 ].…”

Highly-efficient electrochemical label-free immunosensor for the detection of ochratoxin A in coffee samples

“…2B (curve i) shows the modification with PdNPs increases the electrochemical active surface area. The amplification of electrochemical signal and the enhancement of the electron transfer rate of the sensor are due to the excellent electrocatalytic activity of PdNPs [41]. After immobilization of anti-OTA (curve ii) onto PdNPs/CF electrode, a remarkable decrease of the charge transfers resistance (Rct) is observed.…”