Quantum Dots for Cancer-Related miRNA Monitoring

Abstract

Quantum dots (QDs) possess exceptional optoelectronic properties that enable their use in the most diverse applications, namely, in the medical field. The prevalence of cancer has increased and has been considered the major cause of death worldwide. Thus, there has been a great demand for new methodologies for diagnosing and monitoring cancer in cells to provide an earlier prognosis of the disease and contribute to the effectiveness of treatment. Several molecules in the human body can be considered relevant as cancer markers. Studies published over recent years have revealed that micro ribonucleic acids (miRNAs) play a crucial role in this pathology, since they are responsible for some physiological processes of the cell cycle and, most important, they are overexpressed in cancer cells. Thus, the analytical sensing of miRNA has gained importance to provide monitoring during cancer treatment, allowing the evaluation of the disease’s evolution. Recent methodologies based on nanochemistry use fluorescent quantum dots for sensing of the miRNA. Combining the unique characteristics of QDs, namely, their fluorescence capacity, and the fact that miRNA presents an aberrant expression in cancer cells, the researchers created diverse strategies for miRNA monitoring. This review aims to present an overview of the recent use of QDs as biosensors in miRNA detection, also highlighting some tutorial descriptions of the synthesis methods of QDs, possible surface modification, and functionalization approaches.

Trioctylphosphine- and Octanethiol-Induced Photoluminescence Recovery of CdSe/ZnS Quantum Dots after Dilution–Quenching: Implications for Quantum Dot Films

“…Due to the quantum confinement effect, QDs have unique size-tunable electronic structures and optical properties. Moreover, QDs are characterized by wide absorption, narrow emission, high photoluminescence quantum yield (PLQY), good chemical stability and photostability, and good solution processability; therefore, QDs are widely used in the realms of display, lighting, biological imaging, etc. − With continuous efforts of researchers, the syntheses of QDs have been rapidly refined. Some studies are milestones for the synthesis of QDs.…”

A Multicomponent Nucleic Acid Enzyme-Cleavable Quantum Dot Nanobeacon for Highly Sensitive Diagnosis of Tuberculosis with the Naked Eye

“…According to the UV absorption spectrum of BHQ2 and the fluorescence emission spectrum of QD-NB, it could be seen that these two spectra absolutely overlapped, suggesting that the fluorescence resonance energy transfer (FRET) process from QDs to BHQ2 could be achieved (Figure 2A). 41 To demonstrate the fluorescence "on" to "off" process of QD-NB, the fluorescence emission spectra of QD-NB before and after annealing were recorded respectively. As illustrated in Figure 2B, the fluorescence intensity of QD-NB significantly decreased after annealing.…”

Nanomaterials for miRNA detection: the hybridization chain reaction strategy

“…Moreover, miRNA detection comprises the interactions for miRNA hybridization via signal changes and could lead to biorecognition and hairpin-shaped probes. The active surface in fabricated nanomaterials is helpful for rapid HCR in miRNA recognition 52,53 . The presence of functional sites in DNA-fabricated nanomaterials allows the hybridization of miRNA and follows…”

“…The active surface in fabricated nanomaterials is helpful for a rapid HCR in miRNA recognition. 52,53 The presence of functional sites in DNA-fabricated nanomaterials allows the hybridization of miRNA and follows a Watson–Crick base-pairing. 54 This could result in rigid DNA–RNA or RNA–RNA hybrid structures.…”