Biosensing refers to the use of a biological derived or bioinspired receptor to detect the presence of a particular analyte with high specificity. The development of highly sensitive and specific nucleic acids (NA), i.e. DNA or RNA, biosensors has received increasing attention due to their crucial role in diagnostic and therapeutic applications (e.g. detection of disease biomarkers). Especially, the development of multiplexed micro-RNA sensors (miRNA, small non-coding RNAs) due to the role of miRNAs as regulators of gene expression. Overexpression levels can be associated with human diseases such as cancer and today, miRNAs are so-called next-generation biomarkers. Despite the development of methods to analyze NA, such as polymerase chain reaction (PCR), some technical shortcomings still hinder an easy-to-use, reproducible, storable, rapid, sensitive, specific, versatile, and multiplexed NA detection.
Due to the near-infrared (NIR) excitation, multiple and narrow emission bands over a broad wavelength range, and lack of photoblinking and photobleaching, the use of upconversion nanoparticles (UCNPs) offers the opportunity to design highly sensitive multiplexed UCNPs-based sensing probes.
The Upbiosens project describes a novel method to produce a nanobiosensor combining the sensing ability of the DNA strands and the optical properties of the UCNPs as the transducer element to detect and visualize DNA or/and miRNA. Hence, the project addresses the problem of capping UCNPs with DNA while keeping their hybridization capacity as well as controlling the UCNP size, overcoming one of the main limitations of the UCNPs for their application as NA sensors. The outcome of the project can be promisingly bio-implemented, such as in prognosis, diagnostics, and treatment of diseases, gene therapy, or forensic analysis.
