Fabricating an Electrospray Ionization Chip Based on Induced Polarization and Liquid Splitting.

Lvhan Zhou,Qian Zhang,Qian Zhou,Xinming Huo,Xiangchun Xu,Quan Yu,Xiaohao Wang

doi:10.3390/mi12091034

Abstract

The coupling of the microfluidic chip to mass spectrometry (MS) has attracted considerable attention in the area of chemical and biological analysis. The most commonly used ionization technique in the chip–MS system is electrospray ionization (ESI). Traditional chip-based ESI devices mainly employ direct electrical contact between the electrode and the spray solvent. In this study, a microchip ESI source based on a novel polarization-splitting approach was developed. Specifically, the droplet in the microchannel is first polarized by the electric field and then split into two sub-droplets. In this process, the charge generated by polarization is retained in the liquid, resulting in the generation of two charged droplets with opposite polarities. Finally, when these charged droplets reach the emitter, the electrospray process is initiated and both positive and negative ions are formed from the same solution. Preliminary experimental results indicate that the coupling of this polarization-splitting ESI (PS-ESI) chip with a mass spectrometer enables conventional ESI-MS analysis of various analytes.

Highlights

A microfluidic chip, known as a lab on a chip, is a biological, chemical, medical analysis platform for small amounts of fluids and microfluidics [1,2,3]
The formation of charged droplets is the first step in the electrospray ionization (ESI) process
It can be implemented in many ways, but here, we propose a new method based on the polarizationsplitting process of liquid using a unique microchannel structure

Summary

Introduction

A microfluidic chip, known as a lab on a chip, is a biological, chemical, medical analysis platform for small amounts of fluids and microfluidics [1,2,3]. It can process sample preparation, reaction, and detection by using channels of tens to hundreds of micrometers in size [4]. Mass spectrometry (MS) can distinguish and identify chemical compounds by their mass-to-charge ratios It has the characteristics of high sensitivity, fast response, and high precision, and miniaturization has become an important trend in its development [5,6,7,8,9,10]. A miniature mass spectrometer coupled with a microfluidic sample processing device is likely to become a powerful tool for field applications

Methods

Results

Conclusion