Spectral-Phase Interferometry Detection of Ochratoxin A via Aptamer-Functionalized Graphene Coated Glass

Abstract

In this work, we report a novel method of label-free detection of small molecules based on direct observation of interferometric signal change in graphene-modified glasses. The interferometric sensor chips are fabricated via a conventional wet transfer method of CVD-grown graphene onto the glass coverslips, lowering the device cost and allowing for upscaling the sensor fabrication. For the first time, we report the use of graphene functionalized by the aptamer as the bioreceptor, in conjunction with Spectral-Phase Interferometry (SPI) for detection of ochratoxin A (OTA). In a direct assay with an OTA-specific aptamer, we demonstrated a quick and significant change of the optical signal in response to the maximum tolerable level of OTA concentration. The sensor regeneration is possible in urea solution. The developed platform enables a direct method of kinetic analysis of small molecules using a low-cost optical chip with a graphene-aptamer sensing layer.

Detection, Contamination, Toxicity, and Prevention Methods of Ochratoxins: An Update Review

“…Another cutting-edge technology involving aptamer-based detection includes the use of graphene functionalized with aptamers coupled with spectral phase interferometry for the detection of ochratoxins. It can be regenerated using a solution of urea . Aptamers were covalently bound with ochratoxin to construct a biosensor for the detection of OTA.…”

“…using cc-by-4.0 license). Figure B shows a schematic diagram of aptamer-functionalized graphene biosensor coupled with spectral phase interferometry for the detection of ochratoxin (adapted from Nekrasov et al through cc-by-4.0 license) Figure C illustrates the schematic diagram of a graphene field-effect transistor (FET) aptamer-based biosensor …”

“…(A) Fluorescence-based aptamer strip biosensor that is used for the detection of ochratoxin (adapted from Zhang et al through cc-by-4.0 license). (B) Aptamer-functionalized graphene biosensor coupled with spectral phase interferometry for the detection of ochratoxin (adapted from Nekrasov et al through cc-by-4.0 license). (C) Graphene FET aptamer-based biosensor (adapted from Nekrasov et al).…”

Research on sensing characteristics of third‐order runway series symmetric microring resonator based on hybrid plasma waveguide and metal insulator metal

“…Microring resonators are widely used in lasers [1, 2], filters [3–5], optoelectronic modulators [6, 7], optical switches [8], and sensors [9–11] due to their compact structure, functional versatility, scalability and high integration. In recent years, for the advantages of high sensitivity, small size, fast measurement speed, anti‐interference, and direct detection of biological samples, microring label‐free biosensors have attracted the wide attention of scholars [12–15]. Mahdi Bahadoran used the marker‐free biosensor based on a microring resonator made of a slotted silicon waveguide to detect hemoglobin concentration in patients with anemia and realized the sensing line for anemia at different stages, with a sensitivity of 1024 nm/RIU [16].…”

“…scholars [12][13][14][15]. Mahdi Bahadoran used the markerfree biosensor based on a microring resonator made of a slotted silicon waveguide to detect hemoglobin concentration in patients with anemia and realized the sensing line for anemia at different stages, with a sensitivity of 1024 nm/RIU [16].…”