Aptamer-based fluorometric lateral flow assay for creatine kinase MB

Abstract

A group of aptamers possessing high specificity and affinity for creatine kinase MB (CKMB) was obtained by magnetic systematic evolution of ligands by exponential enrichment. Two aptamers (referred to as C.Apt.21 and C.Apt.30) were found to possess adequately low K values. They form a well suited pair for CKMB binding. By using fluorescent microspheres, an aptamer-based lateral flow assay was developed. It is portable, economical, and sensitive. The limit of detection for CKMB is as low as 0.63 ng·mL, and the assay works in the 0.005 - 2 μg·mL CKMB concentration range. The method is specific for CKMB, and biomarkers for AMI (such as cardiac troponin I and myoglobin) and serum do not interfere. The strip is highly accurate as shown by analysis of spiked serum samples which gave recoveries ranging between 88 and 117%. Graphical Abstract Schematic of the test strip and sandwich aptamer-based fluorometric lateral flow assay for creatine kinease. The detection is based on the specific affinity between CKMB and selected aptamers to form a sandwich structure.

A review on advances in methods for modification of paper supports for use in point-of-care testing

“…To satisfy the development of POCT technologies, different types of papers and nanomaterials have been used to fabricate paper-based devices, as illustrated in Table 1. LFA strips, the most commonly used paper-based microfluidic devices for sample detection in POCT, mainly include adsorption pads, NC membranes, conjugate pads, sample pads and back pads [101,105,106]. In LFAs, NC membranes, based on a versatile porous material with nitrate groups on its surface, can immobilize nucleic acids, proteins and other biomolecules through hydrophobic, noncovalent or electrostatic interactions [98].…”

Creatine Kinase-MB measurement using Immunoinhibition methodology. How much is the interference?

“…Recently developed newer assays like Aptamer-based fluorescent assay can be considered as potential assay for CKMB measurement but they are still in the initial stages. 29 These might prove to be beneficial to overcome the interferences caused by macro-CKs encountered with the conventional immunoinhibition methodology.…”

Recent advances in sensitivity enhancement for lateral flow assay

“…Fluorescent labels are generally recommended for low concentrations of targets and quantitative detection. Suitable fluorescent nanoparticles include fluorescent microspheres (FMs) [ 12 ], quantum dots (QDs) [ 11 ], upconverting nanoparticles (UCNPs) [ 13 ], and liposomes with fluorescent dyes [ 14 ]. LFA with non-optical readout can be comparable with that of LFA with fluorescent labels, such as magnetic nanoparticles [ 15 – 17 ] and nanoparticles for electrochemical readings[ 18 – 20 ].…”