Currently, non-communicable diseases (NCDs) have emerged as potential risks for humans due to adopting a sedentary lifestyle and inaccurate diagnoses. The early detection of NCDs using point-of-care technologies significantly decreases the burden and will be poised to transform clinical intervention and healthcare provision. An imbalance in the levels of circulating cell-free microRNAs (ccf-miRNA) has manifested in NCDs, which are passively released into the bloodstream or actively produced from cells, improving the efficacy of disease screening and providing enormous sensing potential. The effective sensing of ccf-miRNA continues to be a significant technical challenge, even though sophisticated equipment is needed to analyze readouts and expression patterns. Nanomaterials have come to light as a potential solution as they provide significant advantages over other widely used diagnostic techniques to measure miRNAs. Particularly, CNDs-based fluorescence nano-biosensors are of great interest. Owing to the excellent fluorescence characteristics of CNDs, developing such sensors for ccf-microRNAs has been much more accessible. Here, we have critically examined recent advancements in fluorescence-based CNDs biosensors, including tools and techniques used for manufacturing these biosensors. Green synthesis methods for scaling up high-quality, fluorescent CNDs from a natural source are discussed. The various surface modifications that help attach biomolecules to CNDs utilizing covalent conjugation techniques for multiple applications, including self-assembly, sensing, and imaging, are analyzed. The current review will be of particular interest to researchers interested in fluorescence-based biosensors, materials chemistry, nanomedicine, and related fields, as we focus on CNDs-based nano-biosensors for ccf-miRNAs detection applications in the medical field.

Cardiovascular disease (CVD) is a serious worldwide health concern that necessitates the development of novel diagnostic techniques for early identification and personalized healthcare management. Even before the insights provided by gut microbiota, current research has demonstrated the importance of circulating microbiome (CMB) in the evolution of cardiometabolic illness risk and progression. We developed a nanobiosensor that uses specific labeled capture probes with perovskite quantum dots (PQDs) to detect the targeted 16S rRNA sequences in the peripheral milieu. With ideal applicability, specificity, and sensitivity, this sensor delivers unique insights into the presence and characterization of circulating microbiota signatures. Developing a nanophotonic microbiome detection method in body fluids may pave the way for creating a distinctive tool for CVD risk prediction for population-based screening programs in low and middle-income countries.