Nanoscale Affinity Double Layer Overcomes the Poor Antimatrix Interference Capability of Aptamers

Abstract

Poor antimatrix interference capability of aptamers is one of the major obstacles preventing their wide applications for real-sample detections. Here, we devise a multiple-function interface, denoted as a nanoscale affinity double layer (NADL), to overcome this bottleneck via in situ simultaneous target enrichment, purification, and detection. The NADL consists of an upper aptamer layer for target purification and sensing and a lower nanoscale solid-phase microextraction (SPME) layer for sample enrichment. The targets flowing through the NADL-functionalized surface are instantly million-fold enriched and purified by the sequential extraction of aptamer and SPME. The formation of the aptamer–target complex is greatly enhanced, enabling ultrasensitive detection of targets with minimized interference from the matrix. Taking the fiber-optic evanescent wave sensor as an example, we demonstrated the feasibility and generality of the NADL. The unprecedented detection of limits of 800, 4.8, 40, and 0.14 fM were, respectively, achieved for three representative small-molecule targets with distinct hydrophobicity (kanamycin A, sulfadimethoxine, and di-(2-ethylhexyl) phthalate) and protein target (human serum albumin), corresponding to 2500 to 3 × 108-fold improvement compared to the sensors without the NADL. Our sensors also showed exceptionally high target specificity (>1000) and tunable dynamic ranges simply by manipulating the SPME layer. With these features comes the ability to directly detect targets in diluted environmental, food, and biological samples at concentrations all well below the tolerance limits.

Evanescent Wave Optical-Fiber Aptasensor for Rapid Detection of Zearalenone in Corn with Unprecedented Sensitivity

“…A EWOF sensor was bought from Beijing Reliance S&T Co. (Beijing, China) and its basic components were described in the literature [ 34 ]. Optical fibers (UV 576/600) were purchased from Beijing Scitlion Technology Co., Ltd. (Beijing, China).…”

“…The modification method of the optical fiber is the same as that reported previously by our group [ 34 , 35 , 37 ]. Briefly, a razor blade was used to strip 3.5 cm of the resin layer at one end of the fiber.…”

“…Due to this limitation, the application of EWOF for the detection of mycotoxins, which typically have low contents within a complex food matrix, is limited [ 32 , 33 ]. Recently, we developed an ultrasensitive evanescent wave optical fiber aptasensor for the detection of small molecules by constructing nanoscale affinity double layer on the fiber (NADL) [ 34 ]. The NADL consists of an aptamer layer and a microextraction layer, which can achieve in situ target purification, detection and in situ target enrichment.…”

Competitive Displacement Triggering DBP Photoelectrochemical Aptasensor via Cetyltrimethylammonium Bromide Bridging Aptamer and Perovskite

“…Alternatively, aptamers are synthetic short-chain oligonucleotide fragments that can specifically recognize various species including proteins, cells, and small molecules. , Compared with antibodies or receptor proteins, aptamers possess higher stability, lower cost, and easier preparation and modification procedures. Since Han et al first designed PAEs aptamers and applied them for the detection of PAEs, the sensors based on aptamers have been developed for the detection of PAEs …”

“…Since Han et al first designed PAEs aptamers 10 and applied them for the detection of PAEs, the sensors based on aptamers have been developed for the detection of PAEs. 11 In recent years, simple and novel photoelectrochemicalbased (PEC) sensors have been developed for the detection of various chemicals and biomolecules in environmental and biological samples. 12,13 The PEC sensor features the characteristics of optical and electrochemical analysis with low cost, fast response, high sensitivity, reduced background, and simple preparation process.…”