Multi-resistive pulse sensor microfluidic device

Abstract

Resistive pulse sensors have been used to characterise everything from whole cells to small molecules. Their integration into microfluidic devices have simplified sample handling whilst increasing throughput. Typically, these devices...

Simple microfluidic device for simultaneous extraction and detection of microplastics in water using DC electrical signal

“…32 However, optical spectroscopy requires sophisticated instruments, is labor-and time intensive, and is cumbersome to provide information about the size and concentration of samples. Using additive manufacturing, Pollard et al 44,47 developed a new multi-RPS sensor to measure particles in the range of 0.1-30 mm. Although their sensor covered a wide range of microplastics, the sensitivity of the sensor to different concentrations was not reported.…”

“…The above electro-fluidic sensors have found a wide range of applications in environmental monitoring of bacteria, 37 algae, 38 heavy metals 39 and most recently, microplastics. 35,[40][41][42][43][44][45] The detection mechanism in C 4 D and RPS is based on monitoring the temporary changes in current caused by translocation of small particles through (or very close to) a sensing gate, which is usually a thin insulating layer in C 4 D sensors and a narrow constriction (orifice) in RPS sensors. [34][35][36] These techniques offer unique advantages in counting and determination of shape and volume estimates for individual particles.…”

“…47 The device design was later improved by integrating a series of RPS sensors into a single 3D-printed device, enabling the sensor to detect a wider range of particles from 0.1 to 30 mm diameter. 44 Yet, the application of RPS sensors for microplastic detection and quantification is limited due to a high chance of channel blockage, requiring additional steps for particle sorting and focusing, 48,49 while being very sensitive to bubbles. 27 Moreover, since the signal generated by the passing particle through the sensing gate is proportional to the volume of the sensing region it occupies, the change in resistance is very small.…”

“…Therefore, advanced signal processing instruments, e.g., lock-in amplifiers or impedance analyzers, are generally required to increase the detection sensitivity and the signal-to-noise ratio, which is more crucial for microplastics smaller than 20 mm. 27,44,47 Recently, new microfluidic RPS sensors have been developed with a sensing orifice at the side wall of the microchannel and multiple voltage input channels. 42 These features significantly reduced the chance of channel blockage and could increase the signal to noise ratio.…”

Recent Progress in Micro- and Nanotechnology-Enabled Sensors for Biomedical and Environmental Challenges

“…In the biomedical field, these devices have enabled the detection and quantification of biological molecules such as proteins and nucleic acids with high accuracy and in real time [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. They have also enabled the development of point-of-care devices that can rapidly diagnose diseases and monitor treatment outcomes [ 31 , 32 , 33 , 34 , 35 ].…”