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Early detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) is the key to controlling the spread of these bacterial infections. An important step in developing biosensors involves identifying reliable sensing probes against specific genetic targets for CT and NG. Here, the authors have designed single‐stranded oligonucleotides (ssDNAs) targeting mutually conserved genetic regions of cryptic plasmid and chromosomal DNA of both CT and NG. The 5′‐ and 3′‐ ends of these ssDNAs are differentially functionalized with thiol groups and coupled with gold nanoparticles (AuNP) to develop absorbance‐based assay. The AuNPs agglomerate selectively in the presence of its target DNA sequence and demonstrate a change in their surface plasmon resonance. The optimized assay is then used to detect both CT and NG DNA extracted from 60 anonymized clinical samples with a clinical sensitivity of ∼100%. The limit of detection of the assays are found to be 7 and 5 copies/µL for CT and NG respectively. Furthermore, it can successfully detect the DNA levels of these two bacteria without the need for DNA extraction and via a lateral flow‐based platform. These assays thus hold the potential to be employed in clinics for rapid and efficient monitoring of sexually transmitted infections. [ABSTRACT FROM AUTHOR]

The improper disposal of hospital waste products containing genetic materials poses a serious safety threat. We present herein an environmentally friendly technology using a graphene-based novel carbon-allotropic surface to remediate such wastes. The used carbon-allotrope is decorated with an enediyne (EDE-1) enriched aromatic pi-conjugated structure to create an efficient and active surface for cleaving DNA strands. Under controlled exposure of ultraviolet (UV) radiation and heat, the developed surface influences genetic degradation without disturbing the bacterial populations present downstream of the water treatment system. The designed material has been extensively characterized using physicochemical and biological tools. Our results indicate that this approach can possibly be introduced in large scale hospital waste disposal streams for remediating genetic hazards and thereby developing a portable self-contained system. [ABSTRACT FROM AUTHOR]

Liquid interfaces facilitate the organization of nanometer‐scale biomaterials with plasmonic properties suitable for molecular diagnostics. Using hierarchical assemblage of 2D hafnium disulfide nanoplatelets and zero‐dimensional spherical gold nanoparticles, the design of a multifunctional material is reported. When the target analyte is present, the nanocomposites' self‐assembling pattern changes, altering their plasmonic response. Using monkeypox virus (MPXV) as an example, the findings reveal that adding genomic DNA to the nanocomposite surface increases the agglomeration between gold nanoparticles and decreases the π‐stacking distance between hafnium disulfide nanoplatelets. Further, this self‐assembled nanomaterial is found to have minimal cross‐reactivity toward other pathogens and a limit of detection of 7.6 pg µL−1 (i.e., 3.57 × 104 copies µL−1) toward MPXV. Overall, this study helped to gain a better understanding of the genomic organization of MPXV to chemically design and develop targeted nucleotides. The study has been validated by UV–vis spectroscopy, X‐ray diffraction, scanning transmission electron microscopy, surface‐enhanced Raman microscopy and electromagnetic simulation studies. To the best knowledge, this is the first study in literature reporting selective molecular detection of MPXV within a few minutes and without the use of any high‐end instrumental techniques like polymerase chain reactions. [ABSTRACT FROM AUTHOR]

Airborne spread of coronavirus disease 2019 (COVID‐19) by infectious aerosol is all but certain. However, easily implemented approaches to assess the actual environmental threat are currently unavailable. We present a simple approach with the potential to rapidly provide information about the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in the atmosphere at any location. We used a portable dehumidifier as a readily available and affordable tool to collect airborne virus in the condensate. The dehumidifiers were deployed in selected locations of a hospital ward with patients reporting flu‐like symptoms which could possibly be due to COVID‐19 over three separate periods of one week. Samples were analyzed frequently for both virus envelope protein and SARS‐CoV‐2 RNA. In several samples across separate deployments, condensate from dehumidifiers tested positive for the presence of SARS‐CoV‐2 antigens as confirmed using two independent assays. RNA was detected, but not attributable to SARS‐CoV‐2. We verified the ability of the dehumidifier to rapidly collect aerosolized sodium chloride. Our results point to a facile pool testing method to sample air in any location in the world and assess the presence and concentration of an infectious agent to obtain quantitative risk assessment of exposure, designate zones as "hot spots" and minimize the need for individual testing which may often be time consuming, expensive, and laborious. [ABSTRACT FROM AUTHOR]

Tracking the viral progression of SARS-CoV-2 in COVID-19 infected body tissues is an emerging need of the current pandemic. Imaging at near infrared second biological window (NIR-II) offers striking benefits over the other technologies to explore deep-tissue information. Here we design, synthesise and characterise a molecular probe that selectively targets the N-gene of SARS-CoV-2. Highly specific antisense oligonucleotides (ASOs) were conjugated to lead sulfide quantum dots using a UV-triggered thiol–ene click chemistry for the recognition of viral RNA. Our ex vivo imaging studies demonstrated that the probe exhibits aggregation induced NIR-II emission only in presence of SARS-CoV-2 RNA which can be attributed to the efficient hybridisation of the ASOs with their target RNA strands. [ABSTRACT FROM AUTHOR]

When nanoparticles encounter a biological fluid, proteins, lipids, and other biomolecules adsorb on the nanoscale surface consequently leading to the evolution of a protein shell or "corona." The corona formed is dynamic in nature and depends on the "synthetic identity" of the NPs, ultimately affecting their biological response. In this paper, an integrated microfluidic platform coupled with an electrical resistance measurement setup is developed to monitor and investigate the real‐time formation of a biomolecular corona of carbon nanoparticles. "Soft" and "hard" corona formation stages are effectively discriminated based on their nanoscale surface chemistries when combined with a time‐frequency tool known as wavelet transform and machine‐learning techniques. Additionally, the corona and its composition are studied using different techniques such as dynamic light scattering, nanoparticle tracking analysis, zeta potential, excitation–emission profiles, 1D sodium dodecyl polyacrylamide gel electrophoresis and subsequently, liquid chromatography‐mass spectrometry analysis. The dynamic setup can eventually be used as a valuable tool for screening of any nanoparticles formulations with distinct surface chemistries for the purpose of reduced protein adsorption/weaker protein corona formation and consequently enhance the success of targeted drug delivery. [ABSTRACT FROM AUTHOR]

In the article "Highly-Specific Single-Stranded Oligonucleotides and Functional Nanoprobes for Clinical Determination of Chlamydia Trachomatis and Neisseria Gonorrhoeae Infections," Dipanjan Pan and his team present a new method for detecting Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections. They design single-stranded DNA probes that target specific genetic segments of CT and NG and attach them to gold nanoparticles. The probes bind to the target gene sequences unique to CT or NG, allowing for an absorbance-based assay. The method is validated using clinical samples and demonstrates high sensitivity and specificity. [Extracted from the article]

In this work, an ultra-sensitive electrochemical-digital sensor chip is devised for potential use as a digital stress analyzer for point-of-care testing (POCT) and preventive on-site recording of the hormone ‘cortisol’, a glucocorticoid class of steroid hormone present in the human saliva. The sensor was interfaced and re-configured with a high precision impedance converter system (AD5933) and used for electrochemical impedance spectroscopy (EIS) to evaluate the cortisol levels in seven saliva samples. To obtain enhanced biological (cortisol) recognition and achieve a lower limit of detection 0.87 ± 0.12 pg mL−1 (2.4 ± 0.38 pmol mL−1) with a wide range from 1 pg mL−1 to 10 ng mL−1 (2.75 pmol mL−1 to 27.58 pmol mL−1; R2 = 0.9831), bovine serum albumin (1% BSA) was utilized as an effective sensitivity enhancer in addition to optimizing the other two parameters: (i) anti-cortisol antibody (anti-CAb) covalently attached to micro-Au electrodes and (ii) saliva sample incubation time on the sensor chip. The results obtained in this work were corroborated with the gold standard ELISA test with an accuracy of 96.3% and other previously reported biosensors. We envisage that the conceivable standpoint of this study can be a practice towards new development in cortisol biosensing, which will be pertinent to POCT targeted for in vitro psychobiological study on patient cortisol in saliva, and finally an implantable sensor chip in the future. [ABSTRACT FROM AUTHOR]