Microfluidic flow-injection aptamer-based chemiluminescence platform for sulfadimethoxine detection

Abstract

Gold nanoparticle–catalyzed chemiluminescence (CL) of luminol is an attractive alternative to strategies relying on enzymes, as their aggregation leads to significantly enhanced CL signals. Consequently, analytes disturbing such aggregation will lead to an easy-to-quantify weakening of the signal. Based on this concept, a homogeneous aptamer-based assay for the detection of sulfadimethoxine (SDM) has been developed as a microfluidic CL flow-injection platform. Here, the efficient mixing of gold nanoparticles, aptamers, and analyte in short channel distances is of utmost importance, and two-dimensional (2D) and three-dimensional (3D) mixer designs made via Xurography were investigated. In the end, since 2D designs could not provide sufficient mixing, a laminated 3D 5-layer microfluidic mixer was developed and optimized with respect to mixing capability and observation by the charge-coupled device (CCD) camera. Furthermore, the performance of standard luminol and its more hydrophilic derivative m-carboxy luminol was studied identifying the hydrophilic derivative to provide tenfold more signal enhancement and reliable results. Finally, the novel detection platform was used for the specific detection of SDM via its aptamer and yielded a stunning dynamic range over 5 orders of magnitude (0.01–1000 ng/ml) and a limit of detection of 4 pg/ml. This new detection concept not only outperforms other methods for SDM detection, but can be suggested as a new flow-injection strategy for aptamer-based rapid and cost-efficient analysis in environmental monitoring and food safety. Graphical abstract

Dual fluorescent aptasensor for simultanous and quantitative detection of sulfadimethoxine and oxytetracycin residues in animal-derived foods tissues based on mesoporous silica

“…The recovery formula was: (measured concentration/added concentration) x 100%. Each concentration was measured five times ( 12 ).…”

“…Sensors based on aptamers as signal probes are of particular interest due to their good selectivity for target molecules and stability in complex physicochemical environments ( 11 ). Recently, various aptasensors have been used to detect SDM and OTC residues, such as chemiluminescence ( 12 , 13 ), electrochemical ( 14 , 15 ), colorimetric ( 16 , 17 ), fluorescence ( 18 , 19 ). These methods have the advantages of high sensitivity and specificity but can only be used to detect a single target.…”

On the Use of Polymer-Based Composites for the Creation of Optical Sensors: A Review

“…The ability to control both the biological responses of the cultured cells and the cell culture conditions is the most important aspect of these systems. On-chip integration of in situ analysis methods provides improved temporal resolution, faster readouts and continuous measurements of such properties as the metabolic activity, the release of particular molecules, rate of proliferation and differentiation [ 240 ]. Therefore, the developed models of organs and diseases could provide more information.…”

“…The aggregation of NPs leads to significantly enhanced CL signals, therefore substances disturbing such a process will lead to weakening of the signal that could be easily detected. An example of the use of such a concept was demonstrated in the detection of sulfadimethoxine (SDM) using the CL microfluidic flow-injection platform with homogeneous aptamer-based assay measurement [ 240 ]. The most important for the successful implementation of the method is the efficient mixing of the components, i.e., AuNPs, aptamers, and analyte.…”

Optical Oxygen Sensing and Clark Electrode: Face-to-Face in a Biosensor Case Study

“…To achieve this goal, we decided to use microfluidic technology due to a number of advantages [ 24 , 25 , 26 , 27 , 28 ]. It allows for minimizing the volume of the analyzed sample, achieving good reproducibility of the hydrodynamic and temperature conditions of the experiment, which leads to a decrease in the dispersion of readings.…”