Ultrasensitive Multianalyte Electrochemical Immunoassay Based on Metal Ion Functionalized Titanium Phosphate Nanospheres

Abstract

A novel multianalyte electrochemical immunoassay was developed for ultrasensitive detection of human cardiopathy biomarkers cardiac troponin I (cTnI) and human heart-type fatty-acid-binding protein (FABP) using metal ion functionalized titanium phosphate nanospheres (TiP-metal ion) as labels. The metal ions could be detected directly through square wave voltammetry (SWV) without metal preconcentration, and the distinct voltammetric peaks had a close relationship with each sandwich-type immunoreaction. The position and size of the peaks reflected the identity and level of the corresponding antigen. The large amount of metal ions loading on the TiP nanospheres greatly amplified the detection signals, and the good biocompatibility of graphene nanoribbons (GONRs) retained good stability for the sandwich-type immunoassay. The proposed immunoassay exhibited high sensitivity and selectivity for the detection of cTnI and FABP. The linear relationships between electrochemical signals and the concentrations of cTnI and FABP were obtained in the range of 0.05 pg/mL-50 ng/mL and 0.05 pg/mL-50 ng/mL, respectively. The detection limits of cTnI and HIgG were 1 and 3 fg/mL (S/N = 3), respectively. Moreover, the immunoassay accurately detected the concentrations of cTnI and FABP in human serum samples, which were demonstrated to have excellent correlations with the standard enzyme linked immunosorbent assay (ELISA) method. The results suggested that the electrochemical immunoassay would be promising in the point-of-care diagnostics application of clinical screening of acute myocardial infarction (AMI) biomarkers.

An ultrasensitive squamous cell carcinoma antigen biosensing platform utilizing double-antibody single-channel amplification strategy

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Metallic nanocrystallites-incorporated ordered mesoporous carbon as labels for a sensitive simultaneous multianalyte electrochemical immunoassay

“…According to the documented method (Feng et al, 2012), the OMC-Zn and OMC-Cd products were dispersed in 6 mL of DI water to get a dispersion of OMC-Zn and OMC-Cd solutions with the concentration of 12 mg/mL. Next, 5 mL of the OMC-M solution was dispersed in 1 mL of PAH (2 mg/mL) aqueous solution and sonicated for 40 min.…”

“…Particularly its abundant amino groups, good biocompatibility and excellent film-forming ability, it was employed for immobilizing the nanocomposites and preventing leakage of MWCNTs (Lai et al, 2011;Fang et al, 2014). In this contribution, we used the MWCNTs-CS composite modified electrode, which was further used for the immobilization of primary antibody (Ab 1 ) enhancing the sensitivity and the stability of the immunosenosr (Lai et al, 2011;Feng et al, 2012).…”

A “signal-on’’ aptasensor for simultaneous detection of chloramphenicol and polychlorinated biphenyls using multi-metal ions encoded nanospherical brushes as tracers

“…Quantum dots (Hansen et al, 2006a(Hansen et al, , 2006b, methylene blue (Jiang et al, 2015), ferrocene , thionine have been widely used as the signal tracers in the traditional reports. Among them, the metallic nanoparticles or quantum dots have attracted much attention due to their extremely high sensitivity (Feng et al, 2012). Moreover, metal ions in the metallic nanoparticles, such as Cd 2 þ , Pb 2 þ and Zn 2 þ can be easily and simultaneously detected by stripping voltammetry, because of the different electrochemical oxidation-reduction potential.…”