A disposable electrochemical sensor based on electrospinning of molecularly imprinted nanohybrid films for highly sensitive determination of the organotin acaricide cyhexatin

Graphene Incorporated Electrospun Nanofiber for Electrochemical Sensing and Biomedical Applications: A Critical Review

The extraordinary material graphene arrived in the fields of engineering and science to instigate a material revolution in 2004. Graphene has promptly risen as the super star due to its outstanding properties. Graphene is an allotrope of carbon and is made up of sp²-bonded carbon atoms placed in a two-dimensional honeycomb lattice. Graphite consists of stacked layers of graphene. Due to the distinctive structural features as well as excellent physico-chemical and electrical conductivity, graphene allows remarkable improvement in the performance of electrospun nanofibers (NFs), which results in the enhancement of promising applications in NF-based sensor and biomedical technologies. Electrospinning is an easy, economical, and versatile technology depending on electrostatic repulsion between the surface charges to generate fibers from the extensive list of polymeric and ceramic materials with diameters down to a few nanometers. NFs have emerged as important and attractive platform with outstanding properties for biosensing and biomedical applications, because of their excellent functional features, that include high porosity, high surface area to volume ratio, high catalytic and charge transfer, much better electrical conductivity, controllable nanofiber mat configuration, biocompatibility, and bioresorbability. The inclusion of graphene nanomaterials (GNMs) into NFs is highly desirable. Pre-processing techniques and post-processing techniques to incorporate GNMs into electrospun polymer NFs are precisely discussed. The accomplishment and the utilization of NFs containing GNMs in the electrochemical biosensing pathway for the detection of a broad range biological analytes are discussed. Graphene oxide (GO) has great importance and potential in the biomedical field and can imitate the composition of the extracellular matrix. The oxygen-rich GO is hydrophilic in nature and easily disperses in water, and assists in cell growth, drug delivery, and antimicrobial properties of electrospun nanofiber matrices. NFs containing GO for tissue engineering, drug and gene delivery, wound healing applications, and medical equipment are discussed. NFs containing GO have importance in biomedical applications, which include engineered cardiac patches, instrument coatings, and triboelectric nanogenerators (TENGs) for motion sensing applications. This review deals with graphene-based nanomaterials (GNMs) such as GO incorporated electrospun polymeric NFs for biosensing and biomedical applications, that can bridge the gap between the laboratory facility and industry.

Graphene impregnated electrospun nanofiber sensing materials: a comprehensive overview on bridging laboratory set-up to industry

Owing to the unique structural characteristics as well as outstanding physio-chemical and electrical properties, graphene enables significant enhancement with the performance of electrospun nanofibers, leading to the generation of promising applications in electrospun-mediated sensor technologies. Electrospinning is a simple, cost-effective, and versatile technique relying on electrostatic repulsion between the surface charges to continuously synthesize various scalable assemblies from a wide array of raw materials with diameters down to few nanometers. Recently, electrospun nanocomposites have emerged as promising substrates with a great potential for constructing nanoscale biosensors due to their exceptional functional characteristics such as complex pore structures, high surface area, high catalytic and electron transfer, controllable surface conformation and modification, superior electric conductivity and unique mat structure. This review comprehends graphene-based nanomaterials (GNMs) (graphene, graphene oxide (GO), reduced GO and graphene quantum dots) impregnated electrospun polymer composites for the electro-device developments, which bridges the laboratory set-up to the industry. Different techniques in the base polymers (pre-processing methods) and surface modification methods (post-processing methods) to impregnate GNMs within electrospun polymer nanofibers are critically discussed. The performance and the usage as the electrochemical biosensors for the detection of wide range analytes are further elaborated. This overview catches a great interest and inspires various new opportunities across a wide range of disciplines and designs of miniaturized point-of-care devices.

Electrochemical assay of ampicillin using Fe3N-Co2N nanoarray coated with molecularly imprinted polymer

Self-supported Fe₃N-Co₂N nanoarray with high electric conductivity and large surface area was prepared for growth of MIPs and further constructing a sensitive and stable electrochemical sensor. For the evaluation of its performance, Fe₃N-Co₂N is used as sensing electrode material, and AMP is used as template molecule to construct the MIP electrochemical sensor. Under the optimized conditions, the developed MIPs electrochemical sensor detects AMP with a low detection limit of 3.65 × 10^-10 mol L^-1 and shows outstanding reproducibility and stability. When the MIPs electrochemical sensor was applied to detect AMP in milk samples via standard addition method, the recovery within 97.06-102.43% with RSD of 1.05-2.11% was obtained. The fabrication of MIPs electrochemical sensor is highly promising for sensitive and selective electrochemical measurement and food safety testing. This work can provide theoretical guidance for truly challenging problems. Graphical abstract Principle diagram of MIP-EC sensor for detecting AMP Molecular imprinted polymers (MIPs) are widely performed for construction of electrochemical (EC) sensors especially for detecting small molecules in complex environment. However, the large-scale and robust preparation of MIPs in situ on sensor platform limits their practical applications. We fabricated a MIPs EC sensor based on Fe₃N-Co₂N in situ grown on carbon cloth (CC) as the substrate platform (Fe₃N-Co₂N/CC) combining with MIPs as the target recognition element for the label-free detection of AMP. Under the optimal conditions, the developed MIPs EC sensor can detect AMP with a low detection limit of 3.65 × 10^-10 mol L^-1. When the AMP in milk is detected by the proposed EC sensor, it shows ideal results. Therefore, the use of self-supported Fe₃N-Co₂N nanoarray as the platform for the fabrication of MIPs EC sensors is highly promising for sensitive and selective EC measurement and point-of-care testing.