Nanomaterials-based biosensor and their applications: A review

A sensor can be called ideal or perfect if it is enriched with certain characteristics viz., superior detections range, high sensitivity, selectivity, resolution, reproducibility, repeatability, and response time with good flow. Recently, biosensors made of nanoparticles (NPs) have gained very high popularity due to their excellent applications in nearly all the fields of science and technology. The use of NPs in the biosensor is usually done to fill the gap between the converter and the bioreceptor, which is at the nanoscale. Simultaneously the uses of NPs and electrochemical techniques have led to the emergence of biosensors with high sensitivity and decomposition power. This review summarizes the development of biosensors made of NPssuch as noble metal NPs and metal oxide NPs, nanowires (NWs), nanorods (NRs), carbon nanotubes (CNTs), quantum dots (QDs), and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.

Carbon Nanomaterial-Based Drug Sensing Platforms Using State-of-the- Art Electroanalytical Techniques

Background:

Currently, nanotechnology and nanomaterials are considered as the most popular and outstanding research subjects in scientific fields ranging from environmental studies to drug analysis. Carbon nanomaterials such as carbon nanotubes, graphene, carbon nanofibers etc. and non-carbon nanomaterials such as quantum dots, metal nanoparticles, nanorods etc. are widely used in electrochemical drug analysis for sensor development. Main aim of drug analysis with sensors is developing fast, easy to use and sensitive methods. Electroanalytical techniques such as voltammetry, potentiometry, amperometry etc. which measure electrical parameters such as current or potential in an electrochemical cell are considered economical, highly sensitive and versatile techniques.

Methods:

Most recent researches and studies about electrochemical analysis of drugs with carbon-based nanomaterials were analyzed. Books and review articles about this topic were reviewed.

Results:

The most significant carbon-based nanomaterials and electroanalytical techniques were explained in detail. In addition to this; recent applications of electrochemical techniques with carbon nanomaterials in drug analysis was expressed comprehensively. Recent researches about electrochemical applications of carbon-based nanomaterials in drug sensing were given in a table.

Conclusion:

Nanotechnology provides opportunities to create functional materials, devices and systems using nanomaterials with advantageous features such as high surface area, improved electrode kinetics and higher catalytic activity. Electrochemistry is widely used in drug analysis for pharmaceutical and medical purposes. Carbon nanomaterials based electrochemical sensors are one of the most preferred methods for drug analysis with high sensitivity, low cost and rapid detection.

Electrochemical oxidation mechanism of eugenol on graphene modified carbon paste electrode and its analytical application to pharmaceutical analysis

Electrochemical properties of eugenol were investigated on a graphene modified carbon paste electrode (CPE) by using voltammetric methods, which exhibited a well-defined irreversible peak at about 0.7V vs Ag/AgCl, NaCl (3M) in Britton-Robinson buffer at pH 2.0. Mechanism of the electrochemical reaction of eugenol was studied by performing density functional theory (DFT) computations and mass spectroscopic analysis. (CPCM:water)-wB97XD/aug-cc-PVTZ//(CPCM:water)-wB97XD/6-31G(d) level calculations predicted that the formation of product P2, possessing a para-quinoid structure, is preferred rather than the product P1, suggested in the literature, having an ortho-quinoid system. Determination of eugenol in a pharmaceutical sample was realized in the light of the electrochemical findings, and a validated voltammetric method for quantitative analysis of eugenol in a pharmaceutical formulation was proposed. The differential pulse voltammogram (DPV) peak currents were found to be linear in the concentration range of 1.0 × 10^-7 to 1.7 × 10^-5M. The limit of detection (LOD) and the limit of quantification (LOQ) were obtained to be 7.0 × 10^-9 and 2.3 × 10^-8, respectively.

Recent advances in hybrid Cu2O-based heterogeneous nanostructures

Hybrid Cu2O-based heterogeneous nanostructures possess novel synergistic properties that arise from the integrated interaction between the disparate components, thereby showing promising potential for various important applications including solar cells, carbon monoxide oxidation, photocatalysts, field emission, sensors, templates and so on. With the rapid progress in nanomaterials science and nanotechnology, hybrid Cu2O-based heterogeneous nanostructures with well-controlled compositions, shapes and sizes have been rationally designed and synthesized. This review attempts to summarize the important advances in the development of different types of hybrid Cu2O-based heterogeneous nanostructures, such as hybrid Cu2O-metal nanostructures, hybrid Cu2O-metal oxide nanostructures and hybrid Cu2O-carbon nanostructures. The correlations between the improved performances and interfacial structures of the hybrid Cu2O-based heterogeneous nanostructures are discussed based on some important and representative examples. Several key scientific issues and perspective research directions in this field are also given.