Metal–Organic Framework Nanomaterials as Novel Signal Probes for Electron Transfer Mediated Ultrasensitive Electrochemical Immunoassay

Abstract

A novel and simple electrochemical immunoassay for C-reactive protein was developed using metal-organic frameworks (Au-MOFs) as signal unit. In this study, we found MOFs could be used as signal probe. And this new class of signal probe differs from traditional probe. The signal of the copper ions (Cu) from MOFs could be directly detected without acid dissolution and preconcentration, which would greatly simplify the detection steps and reduce the detection time. Moreover, MOFs contain large amounts of Cu ions, providing high electrochemical signals. Our report represents the first example of using MOFs themselves as electrochemical signal probe for biosensors. Platinum nanoparticle modified covalent organic frameworks (Pt-COFs) with high electronic conductivity was employed as the substrate, which is the first time demonstrating the use of Pt-COFs for electrochemical immunoassay. Under the optimized experimental conditions, the proposed sensing strategy provides a linear dynamic ranging from 1 to 400 ng/mL. A detection limit of 0.2 ng/mL was obtained, indicating an improved analytical performance. With these merits, this stable, simple, low-cost, sensitive and selective electrochemical immunoassay shows promise for applications in the point-of-care diagnostics of dieses and environmental monitoring.

A sensitive and innovative detection method for rapid C-reactive proteins analysis based on a micro-fluxgate sensor system

“…The results indicated that our fluxgate sensing system is highly sensitive and has a wider linear range when compared with those in recently reported studies. Conversely, the detection limits of a reported photothermal system (PTB) [ 32 ], and a metal-organic framework nanomaterials-based (MOF) electrochemical immunoassay (ECL) technique [ 33 ], or the Molybdenum-disulfide-polyaniline-gold nanoparticles (MoS 2 -PANI-GNPs)-based immunosensor [ 34 ], were significantly lower than that in the current study. However, the PTB sensing technique is based on the photothermal effect, and it therefore needs to be performed under strict temperature monitoring.…”

Enzyme‐free Electrochemical Detection of Hydrogen Peroxide Based on the Three‐Dimensional Flower‐like Cu‐based Metal Organic Frameworks and MXene Nanosheets†

“…[17][18] In addition, the metal ions are bonded to the organic linkers, which are more stable than the free ions. [19] Based on the above advantages, Cu-MOF has been used by researchers to construct electrochemical sensors for the detection of H 2 O 2 , [20] glucose, [21] DNA [8] and diethylstilbestrol. [22] For example, Ling et al [8] designed a sensitive electrochemical DNA detection sensor based on Cu-MOF and allosteric switch of hairpin DNA to achieve highly sensitive detection of target DNA strands.…”

“…[ 17‐18 ] In addition, the metal ions are bonded to the organic linkers, which are more stable than the free ions. [ 19 ] Based on the above advantages, Cu‐MOF has been used by researchers to construct electrochemical sensors for the detection of H 2 O 2 , [ 20 ] glucose, [ 21 ] DNA [ 8 ] and diethylstilbestrol. [ 22 ] For example, Ling et al .…”

The Applications of Metal−Organic Frameworks in Electrochemical Sensors

“…By the use of Cu‐MOF nanomaterials as novel signal probes, a simple electrochemical immunoassay for C‐reactive protein was developed, as shown in Figure . Signal antibody‐modified AuNPs‐MOF composite, in which the antibodies, Cu‐MOFs, AuNPs acted as a complexing agent for recognition layer, a signal probe, and a sensitive promoter, respectively, was constructed for fabrication of the electrochemical sensor.…”