A microfluidic chip containing a molecularly imprinted polymer and a DNA aptamer for voltammetric determination of carbofuran

Abstract

An electrochemical microfluidic chip is described for the determination of the insecticide carbofuran. It is making use of a molecularly imprinted film (MIP) and a DNA aptamer as dual recognition units. The analyte (carbofuran) is transported to the MIP and captured at the identification site in the channel. Then, carbofuran is eluted with carbinol-acetic acid and transported to the DNA aptamer on the testing position of the chip. It is captured again, this time by the aptamer, and detected by differential pulse voltammetry (DPV). The dual recognition (by aptamer and MIP) results in outstanding selectivity. Additionally, graphene oxide-supported gold nanoparticles (GO-AuNPs) were used to improve the sensitivity of electrochemical detector. DPV response is linear in the 0.2 to 50 nM carbofuran concentration range at a potential of -1.2 V, with a 67 pM detection limit. The method has attractive features such as its potential for high throughput, high degree of automation, and high integration. Conceivably, the method may be extended to other analytes for which appropriate MIPs and aptamers are available. Graphical abstract Schematic of an electrochemical microfluidic chip for carbofuran detection based on a molecularly imprinted film (MIP) and a DNA aptamer as dual recognition units. In the chip, targets were recognized by MIP and aptamer, respectively. It shows promising potential for the design of electrochemical devices with high throughput, high automation, and high integration.

Selection and Application of ssDNA Aptamers for Fluorescence Biosensing Detection of Malachite Green

“…In the reaction system of FAM-MG-36-12, the resulting calibration curve for MG detection displayed a good linear relationship in the range of 4–1200 ng/mL with a linear equation y = 0.0033x + 0.3458 and a good linearity correlation coefficient R 2 = 0.9920 ( Figure 4 b). In a statistic process, limit of detection (LOD) and limit of quantitation (LOQ) parameters were typically defined and expressed as LOD = 3σ/S and LOQ = 10σ/S, where σ was standard deviation for blank samples and S was the slope of the standard curve [ 25 , 26 , 27 ]. The LOD and LOQ of the aptasensor were estimated to be 1.82 ng/mL (3.92 nmol/L) and 6.06 ng/mL (13.07 nmol/L), respectively.…”

Molecularly Imprinting–Aptamer Techniques and Their Applications in Molecular Recognition

“…Moreover, Li et al [ 49 ] combined MIPs and aptamers to prepare an electrochemical microfluidic chip for identifying carbofurans in cabbage, pepper, lettuce, tomato, apple, banana, orange and watermelon, as shown in Figure 6 . Carbofuran was transported to MIPs and captured at the recognition site in the channel.…”

“… Fabrication of MIP–aptamer microfluidic chip for the detection of carbofuran. Reproduced with permission from [ 49 ]. Copyright Springer, 2018.…”

ASSURED Point-of-Need Food Safety Screening: A Critical Assessment of Portable Food Analyzers

“…Other notable studies of electrochemical chip-based microfluidic devices developed for food analysis include the use of novel biorecognition elements such as aptamers and molecularly imprinted polymers [ 119 , 120 , 121 ]. The microfluidic chip developed by Lin et al was particularly innovative with a dual recognition platform using both molecularly imprinted polymers and aptamers, to detect carbofuran in vegetable and fruit samples [ 121 ]. Dual recognition improved the selectivity in complex food matrices.…”