Ratiometric Fluorescent Lateral Flow Immunoassay for Point‐of‐Care Testing of Acute Myocardial Infarction

Abstract

We report the development of ah ighly sensitive ratiometric fluorescent lateral flowi mmunoassay( RFLFIA) strip for rapid and accurate detection of acute myocardial infarction biomarker,n amely heart-type fatty acid binding protein (H-FABP). The RFLFIA strip works in terms of ratiometric change of fluorescence signal, arising from blending of fluorescence emitted by two composite nanostructures conjugated to capture and probe antibodies and inner filter effect of gold nanoparticles.Inconjunction with using custom smartphone-based analytical device and tonality analysis, quantitative detection of H-FABP was achieved with al ow limit of detection at 0.21 ng mL À1 .T he RFLFIA strip can generate av isually distinguishable green-to-red color change around the threshold concentration of H-FABP (6.2 ng mL À1 ), thus allowing the semi-quantitative diagnosis by the naked eye.

Emerging biosensing and transducing techniques for potential applications in point-of-care diagnostics

“…158 On this basis, Wang et al developed a new type of ratiometric fluorescence-based LFIA (RFLFIA) strip for naked-eye detection of heart-type fatty acid-binding protein (H-FABP) by using a smartphone. 159 The RFLFIA strip was constructed with suitable reporter and capture probes made from two kinds of quantum dots conjugated with two different types of H-FABP antibodies. The sensing mechanism of RFLFIA involved a target-induced inner filter effect between the two quantum dots, ultimately resulting in a fluorescence color change (from green to red), which was accompanied by a change in the morphology (SEM image) of the strip membrane (Figure 10B).…”

“…Finally, the detection is achieved by using custom smartphone-based analytical device. Reproduced from Ref [159]. with permission.…”

Quantum dots assembly enhanced and dual-antigen sandwich structured lateral flow immunoassay of SARS-CoV-2 antibody with simultaneously high sensitivity and specificity

“…Therefore, a certain false negative cases would be mistakenly considered as non-infectious, resulting in a huge risk of further transmission in the community ( Chen et al, 2020 ; Huang et al, 2013 ; Koller et al, 2021 ). Compared with colorimetric analysis, the fluorometric LFIA provides improved signal contrast and lower background interference ( Huang et al, 2020 ; Wang et al, 2021 ). Quantum dots (QDs) as an emerging class of fluorescent label exhibit high single-particle brightness, none photo-bleaching and versatile nanostructure engineering for integration and functionalization ( Zhou et al, 2015 ).…”

Dual-detection fluorescent immunochromatographic assay for quantitative detection of SARS-CoV-2 spike RBD-ACE2 blocking neutralizing antibody

“…A double-antigen sandwich lateral flow assay that detects SARS CoV-2 specific total antibody has been developed ( Cavalera et al, 2021 ). However, a rapid immunochromatographic assay for neutralizing antibodies against SARS-CoV-2, that enables routine and broadly accessible quantitative detection is still lacking ( Lake et al, 2020 ; Wang et al, 2021a , Wang et al, 2021b ; Zhang et al, 2020 ).…”

“…The classical ratiometric fluorescence assay uses one fluorescence intensity change as a reference to standardize the other changes that occur in response to the same analyte at different wavelengths, thereby providing a built-in self-calibration signal readout. However, only a few reports on the application of these types of ratio principle of fluorescence assays to immunochromatographic assays are currently available ( Wang et al, 2021a , Wang et al, 2021b ).…”