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Nanoconstructs of gold nanoparticles (AuNPs) conjugated with SARS-CoV-2 specific antisense oligonucleotides (ASO) have been utilized to develop sensitive electrochemical nucleic acid biosensor for the detection of SARS-CoV-2 RNA. AuNPs were prepared through a one-pot synthesis method by utilizing Poly-L-Lysine (PLL) biopolymer and as synthesised AuNP were characterized by various analytical techniques such as UV–Vis spectroscopy, X-ray Diffraction (XRD) analysis, Fourier Transform Infra-Red spectroscopy (FT-IR), zeta potential, and Transmission Electron Microscopy (TEM). Poly-L-Lysine functionalized AuNPs (PLL-AuNPs) nanoconstructs platform was employed for immobilization of SARS-CoV-2 specific antisense oligonucleotides (ASO-conjugated PLL-AuNPs) via electrostatic interactions. The PLL-AuNPs were drop casted on glassy carbon electrode (GCE) following immobilization of ASO for fabrication of electrochemical biosensor. The ASO-conjugated PLL-AuNPs nanoconstructs were characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) techniques. The responsiveness of ASO-conjugated PLL-AuNPs nanoconstructs in presence SARS-CoV-2 RNA was monitored using the DPV, SWV and EIS technique, where methylene blue was employed as an electrochemical indicator for DNA-RNA hybridization detection. The biosensor exhibits a detection range for SARS-CoV-2 RNA infection ranging from 0 to 100 nM, with a limit of detection at 30.2 nM. The electrode, modified with ASO-conjugated PLL-AuNPs, was employed for the detection of SARS-CoV-2 RNA from clinical samples collected from COVID-19-positive individuals.

Biological synthesis of gold nanoparticles (AuNPs) is gaining attention of researchers because of their varieties of biomedical applications. This study reported the novel, eco-friendly synthesis of AuNPs using dried fruit extract of Capsicum annum (C. annum). Biosynthesized gold nanoparticles (Ca-AuNPs) showed UV absorption peak at 540 nm and were found to be stable for up to three months. The nanoparticles were further characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FT-IR), Energy Dispersive X-ray Analysis (EDAX) and X-ray diffraction (XRD) analysis. The nanoparticles were spherical in shape with size range of 20–30 nm and zeta potential study confirmed the surface charge of -26.5 mV. The Ca-AuNPs were tested for anti-angiogenic activity using Chorioallantoic membrane (CAM) assay that implied a significant anti-angiogenic efficiency of Ca-AuNPs at 100 µg/mL concentration. The antioxidant activity of Ca-AuNPs studied by 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay was found to be significant with 86.0% radical scavenging activity. These nanoparticles also revealed anti-inflammatory activity at concentration range 100–1200 µg/mL with IC-50 value619.4 µg/mL. The present study includes synthesis of Ca-AuNPs by using phytoconstituents of plant material as reducing agents to efficiently exploit the biomedical applications of the nanoparticles.

Magnetic iron oxide nanoparticle-based multifunctional platforms have been explored extensively in biomedical applications. Modifications and integrations of IONPs with different entities viz. organic polymer, doping with inorganic materials, loading with drug, fluorescent dye, or antibodies make them appropriate for their application in broad spectrum of biomedical fields. This review presents and summarizes the fabrication strategies of multifunctional magnetic nanoparticles based on the modification and surface functionalization of MNP. Multifunctional IONPs based recent advances covering a wide array of applications like biosensing and pathogen detection, magnetic resonance imaging (MRI) and biomarker tracking, magnetofection and gene therapy, hyperthermia and chemotherapy, drug delivery and targeted cell killing, bioimaging and therapeutics, stem cell detection and therapy, tissue engineering and organ transplant, nano-vaccines and immune system activation, microbe targeting and destruction, and COVID19 management are also covered.

Carbon Quantum Dots (CQDs), a type of carbon material having size less than 10 nm and strong fluorescence is creating a new paradigm in the field of bioimaging and other biomedical applications. Owing to simple and low cost of synthesis, tunable and precise optical properties, high photostability and ease of surface functionalization with biological entities there is a huge potential in the field of CQDs based cell imaging applications. A thorough knowledge and understanding of synthesis methods and optical properties are crucial in translation of CQDs based bioimaging research from research lab to commercial purposes for societal benefit. Different methods of synthesis like electrochemical, laser ablation, microwave radiation, and hydrothermal and optical properties like photoluminescent (PL) property, quantum confinement effect, doping influence on optical properties of CQDs are covered in this review. Surface functionalization agents employed for different bio applications have been reviewed along with the current challenges. The applications of CQDs in bioimaging, biosensing and drug delivery along with the existing challenges and future prospects are discussed.

Creatinine is the by-product of creatine phosphate within the muscle, supplying energy to the muscle tissues. It is imperative to clinically assess creatinine levels in both urine and blood as it serves as an indicator of renal, muscle, and thyroid functionality. The point-of-care medical diagnostic research and development is the most innovative form of exploratory research. The determination of creatinine can be achieved through several traditional methods such as colorimetric, spectrophotometric and chromatographic techniques. Although these method offers high sensitivity and selectivity, they are accompanied by drawback such as long analysis time, the need for sample pre-treatment, expensive instruments and skilled personnel. In contrast, sensors and biosensors present a favourable solution to these limitations as they offer rapid, user-friendly, cost effective and highly sensitive alternatives. This review article describe recent trends in creatinine detection by using electrochemical and optical biosensors, advantages and disadvantages of biosensors. This review highlights the wide detection range of creatinine and explore the commercialization aspects of biosensors with in home monitoring system.

Current work reports biogenic synthesis and physico-chemical characterization of silver nanoparticles (AgNPs) by using Aloe barbadensis miller leaves extract (ALE). The prepared biogenic AgNPs have been characterized physico-chemically by X-ray powder diffraction (XRD), UV-visible spectrometry, attenuated total reflectance infrared spectroscopy (ATR-IR), Atomic force microscopy (AFM) and Field emission- scanning electron microscopy (FE-SEM). The characteristic highest absorption peak at 439 nm confirmed the synthesis of AgNPs. Further, the biomedical and catalytic potential of AgNPs was investigated by their anticancer, antioxidative, antimicrobial, and photocatalytic properties. The anticancer potential of AgNPs was evaluated against the breast cancer (MCF-7) cells using MTT cytotoxicity assay. AgNPs proved to be anticancer even for the minimum concentrations of 10 µg/ml, and the anticancer efficiency was increased with increase in concentration. AgNPs showed 42.51% free radical scavenging activity due to their antioxidative nature. 0.3 M AgNPs showed maximum antimicrobial activity with 20 mm zone of inhibition against E. coli bacteria. Additionally, the AgNPs were tested for photocatalytic dye degradation of eosin, crystal violet, carbol fuchsin, methylene blue, and saffranine dyes with maximum % degradation 70.76%, 95.54%, 94.63%, 93.53%, and 90.12%, respectively. The study is unique as the biosynthesized silver nanoparticles by using Aloe barbadensis miller leaves extract shows promising anticancer, antioxidative, antimicrobial, and photocatalytic properties. Herein, the present study reveals the potential of biosynthesized AgNPs for improved therapeutic and catalytic applications.