Electrochemical Immunosensors with PQQ-Decorated Carbon Nanotubes as Signal Labels for Electrocatalytic Oxidation of Tris(2-carboxyethyl)phosphine

Nanocatalysts are a promising alternative to natural enzymes as the signal labels of electrochemical biosensors. However, the surface modification of nanocatalysts and sensor electrodes with recognition elements and blockers may form a barrier to direct electron transfer, thus limiting the application of nanocatalysts in electrochemical immunoassays. Electron mediators can accelerate the electron transfer between nanocatalysts and electrodes. Nevertheless, it is hard to simultaneously achieve fast electron exchange between nanocatalysts and redox mediators as well as substrates. This work presents a scheme for the design of electrochemical immunosensors with nanocatalysts as signal labels, in which pyrroloquinoline quinone (PQQ) is the redox-active center of the nanocatalyst. PQQ was decorated on the surface of carbon nanotubes to catalyze the electrochemical oxidation of tris(2-carboxyethyl)phosphine (TCEP) with ferrocenylmethanol (FcM) as the electron mediator. With prostate-specific antigen (PSA) as the model analyte, the detection limit of the sandwich-type immunosensor was found to be 5 pg/mL. The keys to success for this scheme are the slow chemical reaction between TCEP and ferricinum ions, and the high turnover frequency between ferricinum ions, PQQ. and TCEP. This work should be valuable for designing of novel nanolabels and nanocatalytic schemes for electrochemical biosensors.

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Electrochemical Immunosensors Based on Nanostructured Materials for Sensing of Prostate-Specific Antigen: A Review

Current Medicinal Chemistry ◽

10.2174/0929867328666201124151821 ◽

2020 ◽

Vol 28 ◽

Author(s):

Hayati Filik ◽

Asiye Aslıhan Avan ◽

Mustafa Özyürek

Keyword(s):

Prostate Specific Antigen ◽

Nanostructured Materials ◽

Specific Antigen ◽

Electrochemical Immunosensor ◽

Label Free ◽

Electrochemical Immunosensors ◽

Metal Metal ◽

Different Types ◽

Sandwich Type ◽

Carbon Based Nanomaterials

: The prostate-specific antigen (PSA) has been considered a crucial serological marker for distinguishing prostate based cancer. This surveys recent progress in the construction of nanomaterial-based electrochemical immunosensors for a PSA. This review (from 2015 to 2020) reports the latest progress in PSA sensing based on the employ of different types of nanostructured materials. The most popular used nanostructured materials are metal, metal oxide, carbon-based nanomaterials, and their hybrid architectures utilized for distinct amplification protocols. In this review, the electrochemical immunosensors for prostate-specific antigen sensing are classified into three categories such as sandwich type@labeled, label free@nonlabeled and aptamer-based electrochemical immunosensor.

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Ultrasensitive sandwich-type prostate specific antigen immunosensor based on Ag overgrowth in Pd nano-octahedrons heterodimers decorated on amino functionalized multiwalled carbon nanotubes

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2016.06.160 ◽

2016 ◽

Vol 237 ◽

pp. 733-739 ◽

Cited By ~ 17

Author(s):

Li Liu ◽

Yueyuan Li ◽

Lihui Tian ◽

Qin Wei ◽

Wei Cao

Keyword(s):

Carbon Nanotubes ◽

Prostate Specific Antigen ◽

Multiwalled Carbon Nanotubes ◽

Specific Antigen ◽

Multiwalled Carbon ◽

Sandwich Type ◽

Functionalized Multiwalled Carbon Nanotubes

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Nanocatalysts Containing Direct Electron Transfer-Capable Oxidoreductases: Recent Advances and Applications

Catalysts ◽

10.3390/catal10010009 ◽

2019 ◽

Vol 10 (1) ◽

pp. 9 ◽

Cited By ~ 4

Author(s):

Dalius Ratautas ◽

Marius Dagys

Keyword(s):

Electron Transfer ◽

State Of The Art ◽

Direct Electron Transfer ◽

Biofuel Cells ◽

Solid Surfaces ◽

Electron Mediator ◽

Research Directions ◽

Catalytic Systems ◽

Nanoparticle Catalysts ◽

Nanoparticle Surface

Direct electron transfer (DET)-capable oxidoreductases are enzymes that have the ability to transfer/receive electrons directly to/from solid surfaces or nanomaterials, bypassing the need for an additional electron mediator. More than 100 enzymes are known to be capable of working in DET conditions; however, to this day, DET-capable enzymes have been mainly used in designing biofuel cells and biosensors. The rapid advance in (semi) conductive nanomaterial development provided new possibilities to create enzyme-nanoparticle catalysts utilizing properties of DET-capable enzymes and demonstrating catalytic processes never observed before. Briefly, such nanocatalysts combine several cathodic and anodic catalysis performing oxidoreductases into a single nanoparticle surface. Hereby, to the best of our knowledge, we present the first review concerning such nanocatalytic systems involving DET-capable oxidoreductases. We outlook the contemporary applications of DET-capable enzymes, present a principle of operation of nanocatalysts based on DET-capable oxidoreductases, provide a review of state-of-the-art (nano) catalytic systems that have been demonstrated using DET-capable oxidoreductases, and highlight common strategies and challenges that are usually associated with those type catalytic systems. Finally, we end this paper with the concluding discussion, where we present future perspectives and possible research directions.

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