A Label-Free Electrochemical Immunosensor for CEA Detection on a Novel Signal Amplification Platform of Cu2S/Pd/CuO Nanocomposites

Abstract

Carcinoembryonic antigen (CEA) is regarded as one of the crucial tumor markers for colorectal cancer. In this study, we developed the snowflake Cu2S/Pd/CuO nanocomposite to construct an original label-free electrochemical immunosensor for the ultrasensitive detection of CEA levels. The nanocomposite of cuprous sulfide (Cu2S) with Pd nanoparticles (Pd NPs) was synthesized through an in situ formation of Pd NPs on the Cu2S. Cuprous sulfide (Cu2S) and CuO can not only be used as a carrier to increase the reaction area but also catalyze the substrate to generate current signal. Palladium nanoparticles (Pd NPs) have excellent catalytic properties and good biocompatibility, as well as the ability of excellent electron transfer. The immunosensor was designed using 5 mmol/L H2O2 as the active substrate by optimizing the conditions with a detection range from 100 fg/ml to 100 ng/ml and a minimum detection limit of 33.11 fg/ml. The human serum was detected by electrochemical immunoassay, and the results were consistent with those of the commercial electrochemical immunosensor. Therefore, the electrochemical immunosensor can be used for the detection of human serum samples and have potential value for clinical application.

Reagentless Electrochemical Detection of Tumor Biomarker Based on Stable Confinement of Electrochemical Probe in Bipolar Silica Nanochannel Film

“…The limit of detection (LOD) was calculated to be 0.22 pg/mL based on a signal-to-noise ratio of three (S/N = 3). Table 1 summarizes the analytical performance of various electrochemical methods for the detection of CEA [ 27 , 29 , 50 , 51 , 52 , 53 ]. As seen, the LOD of the fabricated aptamer is only higher than that obtained from the immunosensor fabricated by the immobilization of the CEA antibody (Ab) on cuprous-sulfide–palladium–copper-oxide-modified glassy carbon electrode (Ab/Cu 2 S/Pd/CuO/GCE) [ 50 ].…”

“…Table 1 summarizes the analytical performance of various electrochemical methods for the detection of CEA [ 27 , 29 , 50 , 51 , 52 , 53 ]. As seen, the LOD of the fabricated aptamer is only higher than that obtained from the immunosensor fabricated by the immobilization of the CEA antibody (Ab) on cuprous-sulfide–palladium–copper-oxide-modified glassy carbon electrode (Ab/Cu 2 S/Pd/CuO/GCE) [ 50 ]. In addition, most sensors require time-consuming and laborious procedures, while the developed aptamer sensor does not need the synthesis of complex nanomaterials.…”

Electrochemical and Photoelectrochemical Immunosensors for the Detection of Ovarian Cancer Biomarkers

“…The sensitivity of the biosensor was high, with acceptable selectivity and stability, and could be used in real samples for the detection of CEA. Cao et al [44] established a label-free ultrasensitive EC immunosensor for the rapid detection of CEA, which exhibited an LOD of 33.11 fg/mL with a linear concentration ranging from 100 fg/mL to 100 ng/mL. The construction was based on a cuprous sulfide (Cu 2 S) and palladium nanoparticles (Pd NPs) nanocomposite with CuO.…”