Ultrasensitive FRET-based aptasensor for interleukin-6 as a biomarker for COVID-19 progression using nitrogen-doped carbon quantum dots and gold nanoparticles

Abstract

A label-free and specific FRET-based interleukin-6 (IL-6) aptasensor was developed using a DNA aptamer modified with nitrogen-doped carbon quantum dots (NCDs) and gold nanoparticles (AuNPs) as a donor-quencher pair. The assayed target was capable of disrupting the donor–acceptor assemblies yielding a concentration-related fluorescence recovery of NCDs ( λ em = 445 nm and λ ex = 350 nm). By designing two different probes, the interaction of DNA aptamers with IL-6 protein was studied using FRET efficiency. It appeared that the sensing probes showed slightly different sensing profiles. One of the aptasensors showed a linear response of 1.5–5.9 pg/mL for IL-6 with a coefficient of determination of R 2 ≥ 0.99 and the a detection limit of 0.82 pg/mL (at S/N = 3). The experimental results indicated that the biosensor can be applied to determine IL-6 in human serum (with recovery of 95.7–102.9%). Due to the high sensitivity, excellent selectivity, and simplicity of the procedure, this strategy represents a promising alternative for IL-6 sensing in clinical applications. Graphical Abstract Supplementary Information The online version contains supplementary material available at 10.1007/s00604-022-05570-5.

Rapid assays of SARS-CoV-2 virus and noble biosensors by nanomaterials

“…7 c). Mohamad Mahani et al [ 143 ] reported the FRET-based aptasensor for interleukin-6 as a biomarker for COVID-19 progression using nitrogen-doped carbon quantum dots and gold nanoparticles. Alhadrami et al [ 144 ] reported a colorimetric biosensor of using a cotton swab as a substrate to collect the detected S through the lactoferrin general capture agent, it could specifically bind an orange nanopolymer-modified Ab to produce an optical signature visible to the naked eye, which is available in 5 min and suitable for field detection.…”

Aptamer–Protein Interactions: From Regulation to Biomolecular Detection

“…The fluorophore is spatially separated from the quencher to produce a bright fluorescence signal . By utilizing MBs, researchers have studied specific interactions between aptamers and various proteins, such as thrombin, platelet-derived growth factor (PDGF-BB), Tat protein of HIV-1, and so on. − Additionally, unique optical properties make optical nanomaterials another excellent candidate to develop optical assays . By way of illustration, Ghosh’s group synthesized DNA aptamers targeting glycated albumin (GA) with a quantum dot attached at one end and gold nanoparticle quencher at the other end .…”

“…216−218 Additionally, unique optical properties make optical nanomaterials another excellent candidate to develop optical assays. 219 By way of illustration, Ghosh's group synthesized DNA aptamers targeting glycated albumin (GA) with a quantum dot attached at one end and gold nanoparticle quencher at the other end. 220 Without the addition of GA, the aptamer folded to a hairpin loop structure and the quantum dot fluorescence was quenched by energy transfer to the gold nanoparticle.…”

Optical Nanobiosensor-Based Point-of-Care Testing for Cardiovascular Disease Biomarkers

“…Khakbaz et al reported DNA aptamer immobilized with nitrogen-doped carbon quantum dots (NCDs) based aptasensor system for selective detection of interleukin-6 (IL-6) via a fluorescence resonance energy transfer (FRET) mechanism, and in this system gold nanoparticles (AuNPs) were used as a quencher. 191 Another report also uses carbon dots and palladium−iridium nanocubes-based ratiometric fluorescent immunoassay for selective detection of cTnI with 0.31 pg/mL (LOD) sensitivity. 192 Zhang et al developed a cost-effective FRET sensing platform for the detection of B-type natriuretic peptide (BNP) using graphene oxide (GO).…”

“…Myoglobin aptamer immobilized carbon dots were designed by Wang et al This sensing strategy has the capability of selective and sensitive detection of myoglobin in human serum, urine, and saliva with a linear range from 50 pg/mL to 100 ng/mL, and the detection limit was found to be as low as 20 pg/mL. Khakbaz et al reported DNA aptamer immobilized with nitrogen-doped carbon quantum dots (NCDs) based aptasensor system for selective detection of interleukin-6 (IL-6) via a fluorescence resonance energy transfer (FRET) mechanism, and in this system gold nanoparticles (AuNPs) were used as a quencher . Another report also uses carbon dots and palladium–iridium nanocubes-based ratiometric fluorescent immunoassay for selective detection of cTnI with 0.31 pg/mL (LOD) sensitivity .…”