Male infertility affects up to 12% of the world’s male population and is linked to various environmental and medical conditions. Manual microscope-based testing and computer-assisted semen analysis (CASA) are the current standard methods to diagnose male infertility; however, these methods are labor-intensive, expensive, and laboratory-based. Cultural and socially dominated stigma against male infertility testing hinders a large number of men from getting tested for infertility, especially in resource-limited African countries. We describe the development and clinical testing of an automated smartphone-based semen analyzer designed for quantitative measurement of sperm concentration and motility for point-of-care male infertility screening. Using a total of 350 clinical semen specimens at a fertility clinic, we have shown that our assay can analyze an unwashed, unprocessed liquefied semen sample with <5-s mean processing time and provide the user a semen quality evaluation based on the World Health Organization (WHO) guidelines with ~98% accuracy. The work suggests that the integration of microfluidics, optical sensing accessories, and advances in consumer electronics, particularly smartphone capabilities, can make remote semen quality testing accessible to people in both developed and developing countries who have access to smartphones.

The findings presented here offer a new approach for the environmental application of pollutant soot somewhat like utilizing a pollutant material for degrading the other pollutant material. Herein, a simpler approach is described for the isolation of two-dimensional graphitic materials as water-soluble graphene nanosheets (wsGNS) from the globally identified dirty−dangerous black pollutant particulate matter as black carbon (BC) from the petrol soot. The asisolated wsGNS are further employed for the photocatalytic degradation of toxic dye such as methylene blue (MB) under the influence of visible light irradiation. The photodegradation performance of wsGNS compared to insoluble graphene nanosheets (GNS) showed ∼11 times faster degradation rate within ∼90 min of visible light exposure (60 W tungsten bulb). The insights of the aqueous phase photodegradation of MB by the system of MB-wsGNS were studied by different chemical characterization techniques including nuclear magnetic resonance spectroscopy, high-performance liquid chromatography, Raman, and fourier transform infrared spectroscopy. Furthermore, we have checked the regeneration efficiency of wsGNS, which was still at its higher value even after five cycles of recycling testing.

Water soluble photoluminescent carbon nano-onions were synthesized from vegetable ghee using traditional pyrolytic approach for imaging cells and selective-immediate detection of glucose via fluorescent “turn-off”/“turn-on” technique.

A simple and realistic approach to the utilization of waste "black carbon particulates of petrol soot" for the fabrication of few-layer water-soluble photoluminescent graphene nanosheets (wsGNS) is described herein. Direct transformation of pollutant soot to fluorescent nanocarbons can be a promising approach for providing some economic benefits along with a clean atmosphere. Oxidation of petrol soot resulted in the isolation of the watersoluble version of graphene nanosheets (GNS). Oxidative treatment is a key step in preventing the aggregation of the GNS and rendering them water-soluble. A high degree of "selfpassivation" on wsGNS provides evidence of the tunable photoluminescent emissions over a broad range of the visible spectrum with slight extension in the near-infrared region. The photoluminescent properties of wsGNS are used here for the selective detection of hexavalent chromium ions with a detection limit of 0.51 μM and for imaging HeLa cells.

Herein, a potential approach is described for assessing the ecological importance of the graphitic nanocarbons isolated from dirty, dangerous black pollutant particulate material. A simple experiment of photodegradation and a toxicological test were done using the natural sunlight as a source of energy and the pollutant petrol soot derived water-soluble graphene nanosheets (wsGNS) as photocatalyst to achieve complete degradation of pollutant organic dye as methylene blue (MB). Compared to the artificial source of visible light (60W tungsten bulb), the sunlight-induced photodegradation using wsGNS show ∼1.5 times higher rate of photodegradation. The toxicological test confirmed the nontoxic behavior of wsGNS against the two different types of bacterial strains: Gram-negative and Gram-positive cells, Escherichia coli and Staphylococcus aureus, respectively. Moreover, wsGNS are precisely used for the selective photodegradation of MB without harming the bacterial growth from the pool of MB-bacterial strains. Nontoxicity and selectivity along with the improved in photodegradation efficiencies by wsGNS under the influence of sunlight are the most significant and sustainable perspectives of the present finding.

A high-yield synthesis of water-soluble photoluminescent carbon nanorods is described. The wsCNRs were used for the selective determination of DNA molecules via a fluorescent turn-off/turn-on mechanism.

Rapid antimicrobial susceptibility testing is important for efficient and timely therapeutic decision making. Due to globally spread bacterial resistance, the efficacy of antibiotics is increasingly being impeded. Conventional antibiotic tests rely on bacterial culture, which is time-consuming and can lead to potentially inappropriate antibiotic prescription and up-front broad range of antibiotic use. There is an urgent need to develop point-of-care platform technologies to rapidly detect pathogens, identify the right antibiotics, and monitor mutations to help adjust therapy. Here, we report a biosensor for rapid (<90 min), real time, and label-free bacteria isolation from whole blood and antibiotic susceptibility testing. Target bacteria are captured on flexible plastic-based microchips with printed electrodes using antibodies (30 min), and its electrical response is monitored in the presence and absence of antibiotics over an hour of incubation time. We evaluated the microchip with Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) as clinical models with ampicillin, ciprofloxacin, erythromycin, daptomycin, gentamicin, and methicillin antibiotics. The results are compared with the current standard methods, i.e. bacteria viability and conventional antibiogram assays. The technology presented here has the potential to provide precise and rapid bacteria screening and guidance in clinical therapies by identifying the correct antibiotics for pathogens.

Rapid and sensitive point-of-care diagnostics are of paramount importance for early detection of infectious diseases and timely initiation of treatment. Here, we present cellulose paper and flexible plastic chips with printed graphene-modified silver electrodes as universal point-of-care diagnostic tools for the rapid and sensitive detection of microbial pathogens or nucleic acids through utilizing electrical sensing modality and loop-mediated isothermal amplification (LAMP). We evaluated the ability of the developed paper-based assay to detect (i) viruses on cellulose-based paper microchips without implementing amplification in samples with viral loads between 106 and 108 copies per ml, and (ii) amplified HIV-1 nucleic acids in samples with viral loads between 10 fg µl−1 and 108 fg µl−1. The target HIV-1 nucleic acid was amplified using the RT-LAMP technique and detected through the electrical sensing of LAMP amplicons for a broad range of RNA concentrations between 10 fg µl−1 and 108 fg µl−1 after 40 min of amplification time. Our assay may be used for antiretroviral therapy monitoring where it meets the sensitivity requirement of the World Health Organization guidelines. Such a paper microchip assay without the amplification step may also be considered as a simple and inexpensive approach for acute HIV detection where maximum viral replication occurs.