Portable Aptasensor of Aflatoxin B1 in Bread Based on a Personal Glucose Meter and DNA Walking Machine

Abstract

Despite some recent developments on the portable on-site sensor of Aflatoxin B1 (AFB1), the complex and expensive preparation of recognition elements have still limited their wide applications. In this paper, using the fast, low-cost, and stable recognition of aptamer DNA-AFB1, a portable aptasensor was constructed for the on-site detection of AFB1 in food matrixes, with the readout of personal glucose meter (PGM) and DNA walking machine for signal probe separation. In such an assay protocol, the target could trigger the DNA walker to autonomously move on the electrode surface, propelled by unidirectional Pb-specific DNAzyme digestion, which could amplify the signal and separate the signal probe as well for further quantification by the PGM. Under optimized conditions, the increase of PGM signal was relative with the concentration of AFB1 ranging from 0.02 to 10 nM and the low limit of detection (LOD) was 10 pM (S/N = 3). With the features of portability, and cheapness, the presented user-friendly method could be extended to various other analytes for wide point-of-care applications.

DNA Tetrahedra-Cross-linked Hydrogel Functionalized Paper for Onsite Analysis of DNA Methyltransferase Activity Using a Personal Glucose Meter

“…Now, several portable hand-held-devices, including thermometer, barometer, cellphone, and personal glucose meter (PGM), have been proposed for recording the POCT signals produced by photothermal, pressure-metric, − camera-based, , centrifuge-based, , or glucose-metric − systems. Among these hand-held devices, PGM is a commercially available device, which has been widely utilized for the clinical diagnosis of hyperglycemia owing to its merits of inexpensiveness, reliability, user-friendliness, wide availability, and acceptability in the whole world. , Recently, the application of PGM has been extended to the detection of diverse targets beyond glucose (e.g., toxic metal ions, biological cofactor, and disease marker) through integrating PGM with other enzymes, − which offers a new way for nonglucose targets onsite diagnostics. Nevertheless, most of the reported enzyme-catalyzed generation of glucose is carried out in solution, − and few reports are involved with the direct determination of targets on paper using PGM as a readout.…”

Ingenious Electrochemiluminescence Bioaptasensor Based on Synergistic Effects and Enzyme-Driven Programmable 3D DNA Nanoflowers for Ultrasensitive Detection of Aflatoxin B1

“…In recent years, researchers have been fascinated by the design, construction, and application of electrochemical bioaptasensors (EBAs) − particularly for electrochemiluminescence bioaptasensors (EC-BAs). − EC-BAs, as a promising analytical assay, have received considerable attention and are widely used in the field of bioanalysis. Their utilization in this field can be attributed to two factors: (a) ECL is a redox-induced light emission phenomenon, which possesses electrochemical controllability, high sensitivity, and low background.…”

Near-Infrared Light-Induced Self-Powered Aptasensing Platform for Aflatoxin B1 Based on Upconversion Nanoparticles-Doped Bi2S3 Nanorods

“…Aflatoxins are a secondary metabolite produced by Aspergillus parasiticus and Aspergillus flavus , which has been classified into group I carcinogens. Among the aflatoxins and their derivatives, aflatoxin B1 (AFB1) is one of the most carcinogenic chemical substances known and also the most common one in natural food that is easy to pollute, namely, corn, peanut, and oil made from grain and feed. , The long-term exposure to AFB1 may lead to terrible diseases such as kidney disorders, immune suppression, cell necrosis, and cancer . Many countries have set the maximum tolerant limit of AFB1.…”

“…The self-powered aptasensor was applied to an AFB1 assay in a flour sample using the standard addition method, and the results were compared with those of a commercial enzyme-linked immunosorbent assay (ELISA) kit. The flour was obtained from a local market and pretreated according to a previously reported procedure with a slight modification . Briefly, 5 g of flour sample was immersed in 25 mL of extraction solvent (methanol/water = 5:5 (v/v)).…”

“…The flour was obtained from a local market and pretreated according to a previously reported procedure with a slight modification. 21 Briefly, 5 g of flour sample was immersed in 25 mL of extraction solvent (methanol/water = 5:5 (v/v)). After it was stirred for 1 h, the supernatant was collected via centrifugation at 5000 rpm for 10 min.…”