Platinum Nanoparticle-decorated Graphene Oxide@Polystyrene Nanospheres for Label-free Electrochemical Immunosensing of Tumor Markers

Abstract

We reported the synthesis of novel platinum-nanoparticle-decorated reduced graphene oxide@polystyrene nanospheres (PtNPs@rGO@PS NSs) and their use in developing a novel label-free electrochemical immunosensor for tumor markers. The PtNPs@rGO@PS NSs were fabricated via the electrostatic self-assembly of negatively charged graphene oxide nanosheets onto positively charged PS nanospheres, followed by hydrazine reduction of the GO outer layer and the in situ deposition of PtNPs. The PtNPs@rGO@PS NSs were characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The PtNPs@rGO@PS NSs show a large specific surface area, high electrical conductivity, and good hydrophilicity. The nanospheres were further biofunctionalized with streptavidin and a biotinylated antibody for use as a highly sensitive electrochemical immunosensor for the label-free determination of tumor marker carcinoembryonic antigen (CEA). The fabricated immunosensor detected concentrations of CEA ranging from 0.05 to 70 ng/mL with a detection limit of 0.01 ng/mL, presenting high sensitivity comparable to standard commercial techniques. The nanospheres also showed excellent specificity against other tumor markers and reliability in detection with clinical samples.

Nanostructure-Based Electrochemical Immunosensors as Diagnostic Tools

“…Another method is based on the functionalization of the MeNPs with bifunctional linkers (carboxyl-thiols, amine-thiols) or adapter molecules (streptavidin, biotin) and making them react with the Ab via EDC/NHS chemistry (Figure 2c) [16,19]. Several works employing Au, Pt, Pd, Cu, Ag nanoparticles as electrode materials are found in the literature [20][21][22][23][24][25][26][27][28][29]. However, despite their numerous features, MeNPs are not suitable for sufficient signal amplification by themselves [30].…”

Usage of Platinum Nanoparticles for Anticancer Therapy over Last Decade: A Review

“…The PtNPs@rGO@PS NSs provide a promising potential electrode matrix for many types of biosensing applications and clinical analyses. [116]…”

Electrochemistry/Photoelectrochemistry-Based Immunosensing and Aptasensing of Carcinoembryonic Antigen

“…Some recently reported electrochemical immunosensors for CEA determination are listed in Table 1. For example, Yang's group constructed a novel label-free electrochemical CEA immunosensing platform on the basis of platinum-nanoparticle-decorated reducedgraphene oxide@polystyrene nanospheres (PtNPs@rGO@PS NSs), which were prepared by the hydrazine reduction of graphene oxide (GO) on the surface of PS NSs and the subsequent microwave-induced in situ generation of Pt NPs (Figure 2) [24]. As an ideal electrode matrix, PtNPs@rGO@PS NSs are beneficial for the biofunctionalized modification of streptavidin molecules and the further immobilization of biotinylated CEA antibodies (biotin anti-CEA) due to the fact of their satisfactory biological compatibilities and large specific surface areas.…”

“…Schematic illustration of the preparation process for PtNPs@rGO@PS NSs and the fabrication of the electrochemical label-free immunosensor. Reprinted with permission from ref [24]…”