Hollow spherical nanostructured polydiphenylamine for direct electrochemistry and glucose biosensor

Advancements in Biosensors Based on the Assembles of Small Organic Molecules and Peptides

Over the past few decades, molecular self-assembly has witnessed tremendous progress in a variety of biosensing and biomedical applications. In particular, self-assembled nanostructures of small organic molecules and peptides with intriguing characteristics (e.g., structure tailoring, facile processability, and excellent biocompatibility) have shown outstanding potential in the development of various biosensors. In this review, we introduced the unique properties of self-assembled nanostructures with small organic molecules and peptides for biosensing applications. We first discussed the applications of such nanostructures in electrochemical biosensors as electrode supports for enzymes and cells and as signal labels with a large number of electroactive units for signal amplification. Secondly, the utilization of fluorescent nanomaterials by self-assembled dyes or peptides was introduced. Thereinto, typical examples based on target-responsive aggregation-induced emission and decomposition-induced fluorescent enhancement were discussed. Finally, the applications of self-assembled nanomaterials in the colorimetric assays were summarized. We also briefly addressed the challenges and future prospects of biosensors based on self-assembled nanostructures.

Dipeptide nanostructures: Synthesis, interactions, advantages and biomedical applications

Short peptides are important in the design of self-assembled materials due to their versatility and flexibility. Self-assembled dipeptides, a group of peptide nanostructures, have highly attractive uses in the field of biomedicine. Recently these materials have proved to be important nanostructures because of their biocompatibility, low-cost and simplicity of synthesis, functionality/easy tunability and nano dimensions. Although there are different studies on peptide and protein-based nanostructures, more information about self-assembled nanostructures for dipeptides is still required to discover the advantages, challenges, importance, synthesis, interactions, and applications. This review describes and discusses the self-assembled dipeptide nanostructures especially for biomedical applications.

Poly(diphenylamine) and its Nanohybrids for Chemicals and Biomolecules Analysis: A Review

Background:

This is the first review on Poly(diphenylamine) and its nanohybrids which covers about 181 references demonstrating the brief discussion on the theoretical studies, chemical, electrochemical and other-phase preparation techniques, polymerization and oxidation-reduction (redox) mechanisms, physicochemical and electrochemical properties along with electrochemical sensors and spectroscopic applications on the detection of chemicals and biomolecules analysis applications.

Objective:

The main aim of this detailed report is merely to afford a survey of the literature existing on this multifunctional conducting organic polymer (poly(diphenylamine)) that provokes a pathway to innovations and discoveries in the near future claim its applications in multidisciplinary fields, especially in the detection of chemicals and bio-molecules applications.

Methods:

We discussed the overall studies on poly(diphenylamine) and its various nanohybrids, including copolymers, homopolymers, carbon-based, and metal/metal-oxide hybrids. The different synthesis methods of poly(diphenylamine) such as chemical/electrochemical/mechano-chemical polymerization in terms of morphology and electrical conductivity were briefly discussed.

Conclusion:

This review manuscript deliberates the various synthesis approaches and applications based on the multifunctional conducting polymer poly(diphenylamine) and its nanohybrids. This review provides an outlook and challenges ahead that ignites spotlight to innovations and discoveries in the near future claim its applications in multidisciplinary fields, particularly in electrochemical sensors and spectroscopic applications towards the detection of chemicals and bio-molecules.

Polyaniline nanoflowers grafted onto nanodiamonds via a soft template-guided secondary nucleation process for high-performance glucose sensing

We demonstrated that the electrochemical glucose biosensor fabricated using glucose oxidase-immobilized polyaniline nanoflower-grafted nanodiamonds exhibits superior performances.

Non-enzymatic amperometric sensing of glucose by employing sucrose templated microspheres of copper oxide (CuO)

An enzymeless glucose sensor (MCSPE) based on copper oxide microspheres (CMS) prepared by hydrothermal reaction of copper nitrate and sucrose, can sense glucose in a wide linear detection range with good sensitivity and low detection limit.

A new facile strategy for higher loading of silver nanoparticles onto silica for efficient catalytic reduction of 4-nitrophenol

The facile route to higher loading of silver nanoparticles onto a silica support is useful for large-scale synthesis of efficient silver supported catalysts.

Direct electrochemical deposition of polyaniline nanowire array on reduced graphene oxide modified graphite electrode for direct electron transfer biocatalysis

Direct electron transfer biocatalysis was achieved via electrochemically produced ordered PANI nanowire array on reduced graphene oxide modified graphite electrodes.

An aptamer-based biosensing platform for highly sensitive detection of platelet-derived growth factor via enzyme-mediated direct electrochemistry

In this work, a new label-free electrochemical aptamer-based sensor (aptasensor) was constructed for detection of platelet-derived growth factor (PDGF) based on the direct electrochemistry of glucose oxidase (GOD). For this proposed aptasensor, poly(diallyldimethylammonium chloride) (PDDA)-protected graphene-gold nanoparticles (P-Gra-GNPs) composite was firstly coated on electrode surface to form the interface with biocompatibility and huge surface area for the adsorption of GOD layer. Subsequently, gold nanoclusters (GNCs) were deposited on the surface of GOD to capture PDGF binding aptamer (PBA). Finally, GOD as a blocking reagent was employed to block the remaining active sites of the GNCs and avoid the nonspecific adsorption. With the direct electron transfer of double layer GOD membranes, the aptasensor showed excellent electrochemical response and the peak current decreased linearly with increasing logarithm of PDGF concentration from 0.005 nM to 60 nM with a relatively low limit of detection of 1.7 pM. The proposed aptasensor exhibited high specificity, good reproducibility and long-term stability, which provided a new promising technique for aptamer-based protein detection.

Nanosensors and nanomaterials for monitoring glucose in diabetes

Worldwide, diabetes is a rapidly growing problem that is managed at the individual level by monitoring and controlling blood glucose levels to minimize the negative effects of the disease. Because of limitations in diagnostic methods, significant research efforts are focused on developing improved methods to measure glucose. Nanotechnology has impacted these efforts by increasing the surface area of sensors, improving the catalytic properties of electrodes and providing nanoscale sensors. Here, we discuss developments in the past several years on both nanosensors that directly measure glucose and nanomaterials that improve glucose sensor function. Finally, we discuss challenges that must be overcome to apply these developments in the clinic.