Formation of miRNA Nanoprobes—Conjugation Approaches Leading to the Functionalization

Abstract

Recently, microRNAs (miRNA) captured the interest as novel diagnostic and prognostic biomarkers, with their potential for early indication of numerous pathologies. Since miRNA is a short, non-coding RNA sequence, the sensitivity and selectivity of their detection remain a cornerstone of scientific research. As such, methods based on nanomaterials have emerged in hopes of developing fast and facile approaches. At the core of the detection method based on nanotechnology lie nanoprobes and other functionalized nanomaterials. Since miRNA sensing and detection are generally rooted in the capture of target miRNA with the complementary sequence of oligonucleotides, the sequence needs to be attached to the nanomaterial with a specific conjugation strategy. As each nanomaterial has its unique properties, and each conjugation approach presents its drawbacks and advantages, this review offers a condensed overview of the conjugation approaches in nanomaterial-based miRNA sensing. Starting with a brief recapitulation of specific properties and characteristics of nanomaterials that can be used as a substrate, the focus is then centered on covalent and non-covalent bonding chemistry, leading to the functionalization of the nanomaterials, which are the most commonly used in miRNA sensing methods.

Revealing tumor cells and tissues with high selectivity through folic acid-targeted nanofluorescence probes responsive to acidic microenvironments

“…For instance, the majority of small molecule fluorescent probes exhibit hydrophobic properties and are readily absorbed by the reticuloendothelial system following intravenous administration ( 6 ), consequently leading to a reduced half-life in blood circulation. Furthermore, the utilization of small molecule fluorescent probes often necessitates their conjugation with various biological entities such as antibodies, peptides, and nucleic acids to achieve a certain level of targeting specificity ( 7 – 9 ). However, such binding interactions significantly compromise the sensitivity of in vivo probe detection.…”