Ultrasensitive microchip based on smart microgel for real-time online detection of trace threat analytes

Abstract

Real-time online detection of trace threat analytes is critical for global sustainability, whereas the key challenge is how to efficiently convert and amplify analyte signals into simple readouts. Here we report an ultrasensitive microfluidic platform incorporated with smart microgel for real-time online detection of trace threat analytes. The microgel can swell responding to specific stimulus in flowing solution, resulting in efficient conversion of the stimulus signal into significantly amplified signal of flow-rate change; thus highly sensitive, fast, and selective detection can be achieved. We demonstrate this by incorporating ion-recognizable microgel for detecting trace Pb 2+ , and connecting our platform with pipelines of tap water and wastewater for real-time online Pb 2+ detection to achieve timely pollution warning and terminating. This work provides a generalizable platform for incorporating myriad stimuli-responsive microgels to achieve ever-better performance for real-time online detection of various trace threat molecules, and may expand the scope of applications of detection techniques.

Functional Microgels: Recent Advances in Their Biomedical Applications

“…Microfluidic technique, membrane emulsification, coacervation and desolvation, particle replication in nonwetting templates (PRINT) are some other methods that have also been used in recent years for designing the microgels with the desired properties.…”

Smart hydrogels: Network design and emerging applications

“…By incorporating ion‐recognizable functional materials into the thermo‐responsive PNIPAM, ion‐recognizable hydrogels can be prepared and used for detecting and removing some specific ions. For example, a capillary microchannel has been fabricated with Pb 2+ ‐responsive microgel for detecting a trace Pb 2+ ion via monitoring the change in flow rate . The microgels have been synthesized by crosslinking poly( N ‐isopropylacrylamide‐ co ‐benzo‐18‐crown‐6‐acrylamide) (P(NIPAM‐ co ‐B18C6Am)) copolymer .…”

A Simple Device Based on Smart Hollow Microgels for Facile Detection of Trace Lead(II) Ions

“…Such smart gating membranes can also detect Pb 2+ with concentration of 10 −6 M. The membrane device is simple to operate, but it requires additional pressure for the permeation of solution. The authors’ group also has incorporated a smart microgel into the microfluidic device so that the swelling/shrinking change of the microgel can be efficiently converted into flux change when recognizing Pb 2+ ions, and the detection limit could be as low as 10 −10 M . However, this device still needs a pump to provide additional power for solution flowing.…”