On-Demand Portable Paper-Based Electrospray Ionization Mass Spectrometry for High-Sensitivity Analysis of Complex Samples

Abstract

Paper spray ionization has been demonstrated to be the most promising substrate-based source, but this technique suffers from the low desorption efficiency of target compounds and poor portability. In the current study, we describe a portable paper-based electrospray ionization (PPESI) in which a piece of triangle paper and adsorbent are packed sequentially into a modified disposable micropipette tip. This source not only captures the feature of paper spray and adsorbent for highly efficient suppression of sample matrixes for target compound analysis but also takes advantage of a micropipette tip to prevent spray solvent from rapid evaporation. The performance of developed PPESI depends on the type and amount of packed adsorbent, paper substrate, and spray solvent and applied voltage. Moreover, by contrast to other related sources, the analytical sensitivity and the spray duration of PPESI in tandem with MS have been improved by factors of 2.8−32.3 and 2.0−13.3, respectively. Based on its high accuracy (>96%) and precision (less than 3% relative standard deviation), the PPESI coupled to a mass spectrometer has been used to determine diverse therapeutic drugs and pesticides in complex biological (e.g., whole blood, serum, and urine) and food (e.g., milk and orange juice) matrixes, and the limits of detection and quantification were 2−4 pg mL −1 and 7−13 pg mL −1 , respectively. Taking the portability, high sensitivity, and repeatability, the technique may be a promising alternative for complex sample analysis.

Surface charge-induced electrospray for high-throughput analysis of complex samples and electrochemical reaction intermediates using mass spectrometry

“…In addition, the SCIESI effectively avoids the direct contact between the metal electrode and the sample solution, although its configuration is very similar to the portable paper-based electrospray ionization (PPESI). 21 The above features indicate that the developed SCIESI is promising for high-throughput analysis of various samples.…”

“…S1a†). Analogous to our recent study, 21 the micro-pipette tip is composed of a piece of triangle paper (5 mm at the base and 11 mm in height) with a size of 2 mm extending out of its front tip. An electrospray voltage of 3.5 kV was applied directly to the Cu band around a single electrode through a metal wire (0.3 mm in diameter) in turn.…”

“…19 Inspired by this phenomenon, this study capitalizes on the charge accumulation on a polymer pipette tip, followed by the transfer of HV to the paper substrate wetted with spray solvent. Although the configuration of the developed SCIESI is analogous to paper-based spray ionization [especially paper-based electrospray ionization (PPESI) in our recent study], 20–23 coated blade spray ionization, 24,25 surface-coated aluminium (Al) foil spray 26 and wooden-tip ESI, 27 it effectively eliminates direct contact between the sample solution and metal electrode, paving the way for high-throughput analysis of target compounds in complex samples. By depositing a certain amount of adsorbent on the surface of a paper substrate incorporated into a polymer pipette tip, the analysis sensitivity can be improved by more than 250-fold comparable to the induced nano ESI.…”

Facile and Ultrasensitive Food Allergen Quantification Using Microzone Paper-Based Mass Spectrometric Immunoassay

“…To obtain highly sensitive MT signals, the electrospray voltage, as a significant factor in signal intensity, was focused and optimized. The ion spray voltage was related to the dissociation and ionization of MTs . High voltage contributes to the cleavage of the Au–S bonds.…”

“…The ion spray voltage was related to the dissociation and ionization of MTs. 29 High voltage contributes to the cleavage of the Au−S bonds. The cleavage of MTs was verified by dropping GNP@MTs directly on paper sheets (Figure S8a).…”