The Synergistic Effect of Ferrocene and Cu₂O to Construct a Sandwich-Type Multi-Signal Amplification Ultra-Sensitive Immunosensor for Carcinoembryonic Antigen Detection

Abstract

We reported the first use of "coral-like" nanostructure synthesized from MoS 2 @ Cu 2 O/Fc composites with good biocompatibility, large surface areas, and high specificity to create a new ultrasensitive electrochemical immunosensor. We demonstrate its efficacy via quantitative detection of the carcinogenic fetal antigen (CEA) using labeled antibody (Ab 2 ). Owing to the synergistic effect of MoS 2 , Fc, and Cu 2 O and the excellent electrocatalytic activity of the nanocomposite, our immunosensor could reduce hydrogen peroxide, expand CEA detection signal, and effectively reduce the loss of Cu 2 O in acidic environments, dramatically improving the signal. Monitoring the electrocatalytic processes of our immunoprobe (wide dynamic range [0.001 ngml −1 -80 ng•ml −1 ] and detection limit as low as 0.03 pg•ml −1 [S/N = 3]) with square wave voltammetry (SWV) resulted in the development of an efficient signal amplification mechanism. Our nanostructures could load a large amount of redox-mediated ferrocenecarboxylic acid and Ab 2 , thus providing a higher electrochemical signal response and sensitivity. Specific detection could be implemented during the test, creating the possibility to exhibit acceptable reproducibility, selectivity, and stability. These results suggest that our immunoprobe provides an effective clinical approach for monitoring tumor markers and demonstrate the potential application of composites for immunosensor manufacturing.

Metal Nanoparticles for Electrochemical Sensing: Progress and Challenges in the Clinical Transition of Point-of-Care Testing

“…The authors emphasized that the sensor could be used for the POCT of CEA from human serum. Aside from MNP–carbon material-based composites, metal oxide NPs, core shell MNPs, quantum dot NPs, graphene, MOF, etc., have extensively been studied as the electrode probes for fabricating both labeled or label-free sandwich immunosensing arrays for the ultrasensitive detection of CEA for early-stage cancer diagnoses [ 196 , 202 , 209 , 211 , 212 , 213 , 214 , 215 , 216 ].…”

Handheld Platform for Sensitive Rosiglitazone Detection: Immunosensor Based on a Time-Based Readout Device

“…Compared with other copper-based biomimetic enzymes, Cu 2 O@Au had a lower K m for both TMB and H 2 O 2 (Table S1), indicating that Cu 2 O@Au showed stronger affinity to both TMB and H 2 O 2 . The superior peroxidase activity was attributed to the synergistic effect and the high electron-transfer rate between Cu 2 O and Au …”

MoS2-based nanocomposites for cancer diagnosis and therapy

“…Despite tremendous progress of electrochemical immunosensors have been achieved, ultra-sensitive high-performance immunosensors with multiple amplified signals are still challenging [ 95 ]. In order to further improve their detection performance and amplify detection signal of CEA, the reducing substrate (o-phenylenediamine[o-PD], Cu 2 O, and Ferrocene[Fc]) and enzyme amplifiers were introduced into the detection system of MoS 2 and H 2 O 2 [ [96] , [97] , [98] , [99] ]. Su et al [ 100 ] used MoS 2 nanocomposites (MoS 2 -AuNPs) decorated with gold nanoparticles to construct an enzyme-assisted signal amplification sensor for CEA analysis.…”