Carbon materials on the nanoscale exhibit diverse outstanding properties, rendering them extremely suitable for the fabrication of electrochemical biosensors. Over the past two decades, advances in ...this area have continuously emerged. In this review, we attempt to survey the recent developments of electrochemical biosensors based on six types of carbon nanomaterials (CNs),
i.e.
, graphene, carbon nanotubes, carbon dots, carbon nanofibers, nanodiamonds and buckminsterfullerene. For each material, representative samples are introduced to expound the different roles of the CNs in electrochemical bioanalytical strategies. In addition, remaining challenges and perspectives for future developments are also briefly discussed.
Carbon materials on the nanoscale exhibit diverse outstanding properties, rendering them extremely suitable for the fabrication of electrochemical biosensors. In this review, we survey the recent developments of electrochemical biosensors based on six types of carbon nanomaterials. The remaining challenges and perspectives for future developments are also briefly discussed.
Photoelectrochemical (PEC) biosensing is a newly developed and promising analytical technique. The complete separation of excitation source (light) and detection signal (current) greatly reduces the ...undesired background signal, which is advantageous over both optical and electrochemical determination. Using a photocurrent from the PEC process as a detection signal, PEC biosensor can be operated at a low applied potential and exhibits high sensitivity with repeating cycles. In this account, we summary recent results in the study on PEC biosensing. To construct PEC sensors, exciting light sources of chemiluminescence (CL) and electrochemiluminescence, and PEC active materials including the selected semiconductors, dyes, composites of semiconductors-semiconductors and hybrids of dyes-semiconductors are employed. The principle of PEC biosensing is described and the mechanism in anodic and cathodic photocurrent generation processes is well investigated. On the other hand, in typical PEC biosensors, biomolecules such as antibodies and nucleic acids, are immobilized on the biosensing interface and bind with their corresponding targets via chemical reaction or biological recognition, enabling quantitative detection of the targets possible according to the variation of the photocurrents. Finally, several examples with the PEC biosensing application including immunosensors, DNA sensors, RNA sensors, aptasensors, enzymatic analysis, cytosensors, and detection of small molecules and metal ions are briefly introduced.
Display omitted
•Selective photoelectrochemical architectures for biosensing have been outlined.•The principle and the mechanism of PEC biosensing are presented and summarized.•Exciting light sources for constructing PEC biosensors are well discussed.•The performance of PEC biosensors towards biomolecules is briefly introduced.
The rational design of atomic‐scale interfaces in multiphase nanohybrids is an alluring and challenging approach to develop advanced electrocatalysts. Herein, through the selection of two different ...metal oxides with particular intrinsic features, advanced Co3O4/CeO2 nanohybrids (NHs) with CeO2 nanocubes anchored on Co3O4 nanosheets are developed, which show not only high oxygen vacancy concentration but also remarkable 2D electron gas (2DEG) behavior with ≈0.79 ± 0.1 excess e−/u.c. on the Ce3+ sites at the Co3O4–CeO2 interface. Such a 2DEG transport channel leads to a high carrier density of 3.8 × 1014 cm−2 and good conductivity. Consequently, the Co3O4/CeO2 NHs demonstrate dramatically enhanced oxygen evolution reaction (OER) performances with a low overpotential of 270 mV at 10 mA cm−2 and a high turnover frequency of 0.25 s−1 when compared to those of pure Co3O4 and CeO2 counterparts, outperforming commercial IrO2 and some recently reported representative OER catalysts. These results demonstrate the validity of tailoring the electrocatalytic properties of metal oxides by 2DEG engineering, offering a step forward in the design of advanced hybrid nanostructures.
A novel 2D electron gas (2DEG) behavior, which is realized by integrating CeO2 nanocubes into Co3O4 nanosheets, is demonstrated, and the obtained Co3O4/CeO2 nanohybrids show high electrocatalytic oxygen evolution reaction (OER) performances due to the increased concentration of oxygen vacancies and 2DEG‐promoted high conductivity and electron mobility at the Co3O4–CeO2 interface.
Ultra‐uniform SnOx/carbon nanohybrids for lithium‐ion batteries are successfully prepared by solvent replacement and subsequent electrospinning. The resulting 1D nanostructure with Sn‐N bonding ...between the SnOx and N‐containing carbon nanofiber matrix can not only tolerate the substantial volume change and suppress the aggregation of SnOx, but also enhances the transport of both electrons and ions for the embedded SnOx, thus leading to high cycling performance and rate capability.
A novel nanocomposite, silicon–carbon-based dots@dopamine (Si-CDs@DA) was prepared using (3-aminopropyl) triethoxysilane, glycerol, and dopamine as raw materials via a rapid microwave-assisted ...irradiation. This type of Si-CDs@DA exhibited ultrabright fluorescence emission (quantum yield of 12.4%) and could response to Ag+ selectively and sensitively. Moreover, the obtained Si-CDs@DA can be further applied in sensing intracellular Ag+ and cell imaging, because of its photostability, salt stability, and low cytotoxicity. This study provides a simple and efficient approach for preparing novel Ag+ fluorescent probes, which could expand the application of carbon nanomaterials in designing related biosensors.
In contrast to the extensive investigation of the electrochemical performance of conventional carbon materials in sodium-ion batteries, there has been scarcely any study of sodium storage property of ...fluorine-doped carbon. Here we report for the first time the application of fluorine-doped carbon particles (F-CP) synthesized through pyrolysis of lotus petioles as anode materials for sodium-ion batteries. Electrochemical tests demonstrate that the F-CP electrode delivers an initial charge capacity of 230 mA h g–1 at a current density of 50 mA g–1 between 0.001 and 2.8 V, which greatly outperforms the corresponding value of 149 mA h g–1 for the counterpart banana peels-derived carbon (BPC). Even under 200 mA g–1, the F-CP electrode could still exhibit a charge capacity of 228 mA h g–1 with initial charge capacity retention of 99.1% after 200 cycles compared to the BPC electrode with 107 mA h g–1 and 71.8%. The F-doping and the large interlayer distance as well as the disorder structure contribute to a lowering of the sodium ion insertion–extraction barrier, thus promoting the Na+ diffusion and providing more active sites for Na+ storage. In specific, the F-CP electrode shows longer low-discharge-plateau and better kinetics than does the common carbon-based electrode. The unique electrochemical performance of F-CP enriches the existing knowledge of the carbon-based electrode materials and broadens avenues for rational design of anode materials in sodium-ion batteries.
Tin possesses a high theoretical specific capacity as anode materials for Li-ion batteries, and considerable efforts have been contributed to mitigating the capacity fading along with its huge volume ...expansion during lithium insertion and extraction processes, mainly through nanostructured material design. Herein, we present Sn nanoparticles encapsulated in nitrogen-doped graphene sheets through heat-treatment of the SnO2 nanocrystals/nitrogen-doped graphene hybrid. The specific architecture of the as-prepared Sn@N-RGO involves three advantages, including a continuous graphene conducting network, coating Sn surface through Sn–N and Sn–O bonding generated between Sn nanoparticles and graphene, and porous and flexible structure for accommodating the large volume changes of Sn nanoparticles. As an anode material for lithium-ion batteries, the hybrid exhibits a reversible capacity of 481 mA h g–1 after 100 cycles under 0.1 A g–1 and a charge capacity as high as 307 mA h g–1 under 2 A g–1.
Sheet‐like mimic enzyme: A novel nanostructure (see figure) of sheet‐like FeS with peroxidase‐like activity was synthesized as a mimic enzyme for the development of amperometric transducers and ...biocatalysts.
Artificial enzyme mimics have attracted considerable interest due to easy denaturation and leakage of enzymes during their storage and immobilization procedure. Herein we describe the design of a novel mimic peroxidase, a nanostructure of sheet‐like FeS prepared by a simple micelle‐assisted synthetic method. Such a nanostructure has a large specific surface area and high peroxidase‐like activity, and was thus further used as a mimic enzyme for the development of biocatalysts and amperometric biosensors. The sheet‐like FeS nanostructure showed typical Michaelis–Menten kinetics and good affinity to both H2O2 and 3,3′,5,5′‐tetramethyl benzidine. At pH 7.0 the constructed amperometric sensor showed a linear range for the detection of H2O2 from 0.5 to 150 μM with a correlation coefficient of 0.9998 without any electron transfer mediator. The H2O2 sensor based on the sheet‐like FeS showed more sensitive response than those based on spherical FeS nanostructure, and resulted in a better stability than horseradish peroxidase when they were exposed to solutions with different pH values and temperatures. These excellent properties made the sheet‐like nanostructured FeS powerful tools for a wide range of potential applications as an “artificial peroxidase” as biosensors and biotechnology.
Sheet‐like mimic enzyme: A novel nanostructure (see figure) of sheet‐like FeS with peroxidase‐like activity was synthesized as a mimic enzyme for the development of amperometric transducers and biocatalysts.
On the basis of the absorption and emission spectra overlap, an enhanced resonance energy transfer caused by excition-plasmon resonance between reduced graphene oxide (RGO)-Au nanoparticles (AuNPs) ...and CdTe quantum dots (QDs) was obtained. With the synergy of AuNPs and RGO as a planelike energy acceptor, it resulted in the enhancement of energy transfer between excited CdTe QDs and RGO-AuNPs nanocomposites. Upon the novel sandwichlike structure formed via DNA hybridization, the exciton produced in CdTe QDs was annihilated. A damped photocurrent was obtained, which was acted as the background signal for the development of a universal photoelectrochemical (PEC) platform. With the use of carcinoembryonic antigen (CEA) as a model which bonded to its specific aptamer and destroyed the sandwichlike structure, the energy transfer efficiency was lowered, leading to PEC response augment. Thus a signal-on PEC aptasensor was constructed. Under 470 nm irradiation at −0.05 V, the PEC aptasensor for CEA determination exhibited a linear range from 0.001 to 2.0 ng mL–1 with a detection limit of 0.47 pg mL–1 at a signal-to-noise ratio of 3 and was satisfactory for clinical sample detection. Since different aptamers can specifically bind to different target molecules, the designed strategy has an expansive application for the construction of versatile PEC platforms.
Novel polypyrrole-polyoxometalate/reduced graphene oxide ternary nanohybrids (TNHs) are synthesized via a one-pot redox relay strategy. The TNHs exhibit high areal specific capacitance (2.61 mF ...cm(-2)), and the fabricated solid device also exhibits good rate capability, excellent flexibility and mechanical stability.
