Carbon dots hybrid for dual fluorescent detection of microRNA-21 integrated bioimaging of MCF-7 using a microfluidic platform

Abstract

Background MicroRNAs have short sequences of 20 ~ 25-nucleotides which are similar among family members and play crucial regulatory roles in numerous biological processes, such as in cell development, metabolism, proliferation, differentiation, and apoptosis. Results We reported a strategy for the construction of a dual-emission fluorescent sensor using carbon dots (CDs) and confirmed their applications for ratiometric microRNA-21 sensing and bioimaging of cancer cells in a microfluidic device. The composition of blue CDs (B-CDs) and yellow CDs (Y-CDs) depicts dual-emission behavior which is centered at 409 and 543 nm under an excitation wavelength of 360 nm. With increasing microRNA-21 concentration, the robust and specific binding of DNA probe functionalized B-CDs to complementary microRNA-21 target induced perturbations of probe structure and led to changing fluorescence intensity in both wavelengths. Consequently, the ratio of turn-on signal to turn-off signal is greatly altered. With monitoring of the inherent ratiometric fluorescence variation (ΔF540nm/ΔF410nm), as-prepared BY-CDs were established as an efficient platform for ratiometric fluorescent microRNA-21 sensing, with a wide linear range of 0.15 fM to 2.46 pM and a detection limit of 50 aM. Conclusions Furthermore, the proposed assay was applied for detecting microRNA-21 in dilute human serum samples with satisfactory recovery and also in MCF-7 cell lines in the range 3000 to 45,000 (cell mL−1) with a detection limit (3 cells in 10 μL), demonstrating the potential of the assay for clinic diagnosis of microRNA-associated disease. More importantly, the images revealed that MCF-7 cells well labeled with BY-CDs could exhibit the applicability of the proposed microfluidic system as an effective cell trapping device in bioimaging. Graphical Abstract

Advances in Functionalized Nanomaterial‐incorporated Biosensing Platforms for Detecting Cancer Biomarkers during Biopsies

“…This highly sensitive biosensor detected miRNA-21 with a detection limit of 0.03 pM. Furthermore, Mohammadi et al [17] developed a sensor for the clinical diagnosis of miRNA-associated cancers using dual-colored CDs (blue and yellow CDs). The ratiometric method for miR-21 sensing and bioimaging of cancer cells in a microfluidic device demonstrated a detection limit of 50 aM (Figure 3).…”

“…[93] Meanwhile, Geetha Bai et al [38] utilized a rGOfolic acid (FA) nanocomposite to develop an electrochemical biosensor for detecting the folate receptor (FR)-β protein biomarker and evaluate its response to cancer detection. A GCE was modified with the rGO-FA, and its specific detection toward [17] 2022, Journal of Nanobiotechnology.…”

A Brief Review of Carbon Dots–Silica Nanoparticles Synthesis and their Potential Use as Biosensing and Theragnostic Applications

“…The positively charged PEI molecules served as DNA-binding molecules, and folate served as a receptor. The nanomaterial demonstrated the ability to detect 293 T and HeLa cells and presented plasmid transfection activity [ 56 , 57 ]. Recently, new trends in the applications of CDs have emerged.…”

Carbon dots and miniaturizing fabrication of portable carbon dot-based devices for bioimaging, biosensing, heavy metal detection and drug delivery applications

“…A report based on synthesizing dual-emissive CDs and their respective application in the ratiometric microRNA-21 sensing and bioimaging of cancer cells in a microfluidic device had been postulated. 74 The microfluidic device was first created using the etching technique on a silicon substrate. Then, using the mixture of PDMS and curing agents in an appropriate ratio, a replicate can be made based on the master mould created earlier.…”