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Infectious diseases alone are estimated to result in approximately 40% of the 50 million total annual deaths globally. The importance of basic research in the control of emerging and re-emerging diseases cannot be overemphasized. However, new nanotechnology-based methodologies exploiting unique surface-located glycoproteins or their patterns can be exploited to detect pathogens at the point of use or on-site with high specificity and sensitivity. These technologies will, therefore, affect our ability in the future to more accurately assess risk. The critical challenge is making these new methodologies cost-effective, as well as simple to use, for the diagnostics industry and public healthcare providers. Miniaturization of biochemical assays in lab-on-a-chip devices has emerged as a promising tool. Miniaturization has the potential to shape modern biotechnology and how point-of-care testing of infectious diseases will be performed by developing smart microdevices that require minute amounts of sample and reagents and are cost-effective, robust, and sensitive and specific. The current review provides a short overview of some of the futuristic approaches using simple molecular interactions between glycoproteins and glycoprotein-binding molecules for the efficient and rapid detection of various pathogens at the point of use, advancing the emerging field of glyconanodiagnostics.

Point-of-care (POC) or near-patient testing allows clinicians to accurately achieve real-time diagnostic results performed at or near to the patient site. The outlook of POC devices is to provide quicker analyses that can lead to well-informed clinical decisions and hence improve the health of patients at the point-of-need. Microfluidics plays an important role in the development of POC devices. However, requirements of handling expertise, pumping systems and complex fluidic controls make the technology unaffordable to the current healthcare systems in the world. In recent years, capillary-driven flow microfluidics has emerged as an attractive microfluidic-based technology to overcome these limitations by offering robust, cost-effective and simple-to-operate devices. The internal wall of the microchannels can be pre-coated with reagents, and by merely dipping the device into the patient sample, the sample can be loaded into the microchannel driven by capillary forces and can be detected via handheld or smartphone-based detectors. The capabilities of capillary-driven flow devices have not been fully exploited in developing POC diagnostics, especially for antimicrobial resistance studies in clinical settings. The purpose of this review is to open up this field of microfluidics to the ever-expanding microfluidic-based scientific community.

Metalloids and heavy metal contamination in the environment has become a global problem. Therefore, there is a dire need to develop effective and inexpensive approaches that can facilitate efficient monitoring of the hazardous level of these environmental pollutants. Microbial cell-based and fluorescent protein-based biosensors offer relatively convenient and inexpensive tools for the analysis of environmental pollutants as opposed to traditional instrumental approaches. Small size fluorescent proteins can withstand exposure to denaturants, high temperature and a wide pH range. These characteristics, along with their potential of sensing different toxic analytes, makes them a suitable candidate for developing on-site detection biosensors. The current study exploits the biosensing potential of a novel fluorescent protein called HriCFP. HriCFP was expressed in the prokaryotic system (gram-negative E. coli), which showed stable and discreet expression in bacterial cells. Whole-cell biosensors (WCB) were developed by immobilization of HriCFP expressing non-pathogenic E. coli via nitrocellulose membrane, low melting agarose and sodium silicate gel. These immobilized biosensors were tested for their sensitivity of detection for environmental pollutants, i.e., heavy metals (Cu(II), Hg(II), As(III)). These WCBs exhibited profound fluorescent quenching when exposed to a range of heavy metals. These biosensors remained active for 12 days at 4 °C, demonstrating their potential for long-term stability and storage. This study implies that HriCFP may have a significant advantage over other larger and multimeric proteins as it has a minimal impact on host strain metabolism and hence, increasing its sustainability for a longer period.