Phosphorene has recently gained tremendous interest in the current decade, specifically, black phosphorus monolayer, a unique 2D material, investigation of which has led toward the creation of new scientific discoveries for future optoelectronic sensor devices. Beyond the success of graphene and other 2D layered materials research over the past decades, the increased interest toward this new emerging single-element structured material is because of its layer dependent 0.3–2.0 eV band gap modulation range which is also the band gap modulation range of single- and few-layered graphene and transition metal dichalcogenides (TMDs). Besides that, phosphorene allows strong light-matter interactions at resonance because of its unique physical structure and outstanding electrical and optical properties. Therefore, current advancements are being done to enhance the performance of phosphorene thin films because of its applicability in different fields. This paper is aimed to highlight key properties, applications, and future perspects and challenges incurred regarding the use of 2D layered phosphorene.

This article features the recent developments in fluorographene (FG) and its other functional forms such as fluorographene oxide—their synthesis, fluorination, defluorination, and applications. FG is identified as an important functional derivative of graphene, and FG’s multifunctionalities make it as an ideal candidate for diverse fields, say from photovoltaic to bio-medical diagnosis, imaging, sensing, and therapy. Here the possibilities of FG as a biomedical sensing platform is discussed in detail and the potentials of FG based electrochemical and conductometric sensing platforms are unraveled. The importance of fluorine control as well as the other key factors need to be considered while choosing FG based bio-sensing platforms are also discussed.

Graphene has emerged as a champion material for a variety of applications cutting across multiple disciplines in science and engineering. Graphene and its derivatives have displayed huge potential as a biosensing material due to their unique physicochemical properties, good electrical conductivity, optical properties, biocompatibility, ease of functionalization, and flexibility. Their widespread use in making biosensors has opened up new possibilities for early diagnosis of life-threatening diseases and real-time health monitoring. Following an introduction and discussion on the significance of fabrication protocols and assembly, this review is intended to assess why graphene is suitable to build better biosensors, the working of existing biosensing schemes and their current status toward commercialization for wearable diagnostic and prognostic devices. We believe this review will provide a critical insight for harnessing graphene as a suitable biosensor for the clinical diagnostics, its future prospects and challenges ahead.

Electrochemical sensing systems are advancing into a wide range of new applications, moving from the traditional lab environment into disposable devices and systems, enabling real-time continuous monitoring of complex media. This transition presents numerous challenges ranging from issues such as sensitivity and dynamic range, to autocalibration and antifouling, to enabling multiparameter analyte and biomarker detection from an array of nanosensors within a miniaturized form factor. New materials are required not only to address these challenges, but also to facilitate new manufacturing processes for integrated electrochemical systems. This paper examines the recent advances in the instrumentation, sensor architectures, and sensor materials in the context of developing the next generation of nanoenabled electrochemical sensors for life sciences applications, and identifies the most promising solutions based on selected well established application exemplars.

Graphene due to its unique physicochemical properties mainly its large surface to volume ratio, excellent thermal and electrical conductivity, biocompatibility, as well as broad electrochemical potential, has received considerable attention for biosensing applications. In this review paper, we provide a comprehensive overview of the recent advances in the field of electrochemical biosensors developed using the graphene nanomaterial including graphene oxide, reduced graphene oxide, CVD graphene, and various graphene based nanostructures including nanomesh, nanowalls, etc. in healthcare related applications. The review focusses on material synthesis, device fabrication, and biofunctionalization of graphene electrodes in biosensing such as those based on electrochemical impedance, amperometry/voltammetry, potentiometry, conductometry, and field effect transistor. Additionally, several ingenious biosensing strategies of graphene biosensor in clinical diagnosis for detection of proteins (disease biomarkers), nucleic acids (mutation analysis in genetic diseases), small molecules (disease metabolites like glucose, lactic acid etc.), and pathogens (bacterial and viral infections) have also been discussed.

In recent years, stimuli responsive polymer based gene delivery vehicle design for cancer treatment and treatment of other genetic disorders has received extensive attention. Early studies focusing on DNA delivery have been facilitated by functional polymers and this area has seen further growth spurred by recent gene silencing strategies developed for small RNA [i.e., small interfering RNA (siRNA) or micro RNA (miRNA)] delivery. DNA and small RNAs possess analogous properties; however, their explicit differences define the specific challenges associated with the delivery route and the design of functional materials to overcome distinct challenges. Apart from classical gene delivery, the recent advances in genome editing have revealed the necessity of new delivery devices for genome editing tools. A system involving CRISPR (clustered, regularly interspaced, short palindromic repeats) and an endonuclease CRISPR-associated protein 9 (Cas9) coupled with a short, single-guide RNA (sgRNA) has emerged as a promising tool for genome editing along with functional delivery systems. For all these nucleic acid based treatments, the internal or external physiochemical changes in the biological tissue/cells play a major role in the design of stimuli responsive delivery materials for both in vitro and in vivo applications. This review emphasizes the recent advances in the use of pH, temperature, and redox potential-responsive polymers overcoming hurdles for delivery of gene and gene editing tools for both in vitro and in vivo applications. Specifically the chapter focuses on recently proposed delivery strategies, types of delivery systems, and polymer synthesis/modification methods. The recent advances in CRISPR/Cas9-sgRNA technology and delivery are also described in a separate section. The review ends with current clinical trials, concluding remarks, and future perspectives.

As an atomic-thick layer material, graphene has a large specific surface area, high electron mobility, and high sensitivity to electronic perturbations from the binding of molecules, all of which are attractive properties for developing electronic sensing devices. This article focuses on graphene-based electronic sensors [field effect transistor (FET) sensors] for detecting biomolecules, including DNA, protein, and bacteria, among others. This article will cover three morphologies of graphene materials in biosensing applications: graphene nanosheet, graphene nanoribbon, and vertically-aligned graphene. The unique structure and electronic properties of graphene enable the FET sensor for the low concentration and rapid detection of biomolecules, thereby addressing the limitations of conventional optical sensing technologies such as ELISA, Western Blot, and electrochemical method. The advantages of graphene-based sensing technology are highlighted and recent progress on graphene-based electronic sensors for detecting biomolecules is reviewed and discussed.

We report results of the studies relating to the fabrication of nanostructured zirconia (nZrO2) based immunosensor for cardiac troponin I biomarker (acute myocardial infarction) detection. One step, low temperature hydrothermal process was used for the synthesis of nZrO2 (∼5 nm). This nZrO2 was functionalized with 3-aminopropyl triethoxy silane (APTES) and thereafter it was electrophoretically deposited on to indium tin oxide (ITO) coated glass electrode. EDC/NHS surface chemistry was used for covalent immobilization of monoclonal anti-troponin-I (anti-cTnI) antibodies onto APTES/nZrO2/ITO electrode. The structural, morphological and functional characterization of the synthesized nanoparticles and the fabricated immunoelectrode were conducted via X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and electrochemical techniques. The results of electrochemical response studies of BSA/anti-cTnI/APTES/nZrO2/ITO immunoelectrode reveal that, this platform can be used for efficient detection of cardiac troponin I (cTnI) biomarker with a wide linear detection range (0.1–100 ng/mL) and sensitivity [3.9 µA mL/(ng cm2)].

Single-stranded DNA molecules capable of molecular recognition and catalysis can now be routinely generated via the technique of in vitro selection. When coupled with adequate signal transduction modes, these synthetic functional DNA species represent a potential paradigm shift in the research and development of biosensors to meet the challenges of our rapidly changing world. Coupling functional DNA molecules with graphene materials for the design of optical biosensors has become an exciting research area in recent years, mostly because graphene materials are not only excellent quenchers of fluorescence, but they also display considerably different affinities for free and ligand-bound functional DNA molecules. We will discuss notable progress in this area in this mini-review by highlighting representative studies.

Prompted by the success in functionalizing 2D sheets of MoS2 and MoSe2 by their reaction with organic halides, we have investigated the functionalization of layered tungsten chalcogenides, WS2, WSe2, and WTe2, by their reaction with substituted iodobenzenes as well as fluorophores based on pyrene and coumarin. Carbon–chalcogenide bonds are formed readily in the case of metallic chalcogenides while there is need for the Pd(0) catalysts in the case of insulating chalcogenides. Thus, the formation of carbon–chalcogen (S, Se, and Te) bonds is accomplished with the metallic 1T as well as the semiconducting 2H phases of the tungsten chalcogenides. Functionalization in the case of substituted iodobenzenes is favored by the electron withdrawing groups in the benzene ring. Interestingly, functionalization has been successful with other insulating layered chalcogenides such as GaS and GaSe. Reaction with organic halides emerges as a general method for the covalent functionalization of chalcogenide nanosheets, suggesting the possible use of this strategy to functionalize various chalcogenide structures.

Carbon–nitrogen compounds have attracted enormous attention because of their unusual physical properties and fascinating applications on various devices. Especially in two-dimension, doping of nitrogen atoms in graphene is widely believed to be an effective mechanism to improve the electronic and optoelectronic performances of graphene. In this work, using the first-principles calculations, we systematically investigate the electronic, mechanical, and optical properties of monolayer C3N, a newly synthesized two-dimensional carbon-graphene crystal. The useful results we obtained are: (i) monolayer C3N is an indirect band-gap semiconductor with the gap of 1.042 eV calculated by the accurate hybrid functional; (ii) compared with graphene, it has smaller ideal tensile strength but larger in-plane stiffness; (iii) the nonlinear effect of elasticity at large strains is more remarkable in monolayer C3N; (iv) monolayer C3N exhibits main absorption peak in visible light region and secondary peak in ultraviolet region, and the absorbing ratio between them can be effectively mediated by strain.

Nanoscale biosensor technology has attracted considerable attention with its promise of revolutionizing techniques ranging from biological interfaces to rapid pathogen detection to enabling DNA data storage. Many approaches, such as nanopore sequencing, have been explored and are already achieving tremendous success; however, new sensing modalities and architectures are emerging that are envisioned for the next generation of ever more capable biosensors. These novel devices, combined with advances in machine learning, are moving concepts from simulation to experimentation and demonstration. In recent years, rapid advances have been made and many architectures have been put forward for novel approaches to biomolecular sensing using nanoelectronics, including the advent of tunnel junctions as a sensing platform. With high accuracy, sensitivity, and affordability, these sensors are predicted to drive a shift to personalized medicine and rapid diagnostics in real-time anywhere in the world. Here we give an overview of tunneling sequencing and its application in biomolecular sensing and provide a perspective on the use of scalable tunneling sequencing methods utilizing graphene as the active component.