Issue 4, 2022

A ratiometric fluorescence strategy based on polyethyleneimine surface-modified carbon dots and Eosin Y for the ultrasensitive determination of protamine and trypsin

Abstract

In this work, we report a novel and ultrasensitive dual-signal fluorescence emission detection system for protamine and trypsin based on the electrostatic interaction between polyethyleneimine (PEI) surface-modified positively charged carbon quantum dots (CDs-PEI) and the anionic fluorescent dye Eosin Y. The fluorescence system exhibited yellow-green fluorescence from Eosin Y and blue fluorescence from CDs-PEI. As a cationic peptide, protamine quenched the yellow-green fluorescence of Eosin Y at 542 nm through electrostatic interaction. In the presence of trypsin, protamine was specifically hydrolyzed by trypsin, which led to the subsequent recovery of the fluorescence of Eosin Y. Simultaneously, the blue fluorescence emission of CDs-PEI at 452 nm remained constant during the whole process. Hence, a ratiometric fluorescent nanoprobe for protamine and trypsin detection with high sensitivity was successfully constructed based on CDs-PEI and Eosin Y. For protamine detection, the ratiometric fluorescence intensity (I542/I452) exhibited an excellent linear relationship in the range of 0.1–5.2 μg mL−1 with a limit of detection (LOD) of 0.03 μg mL−1. And the linear relationship between I542/I452 and trypsin concentration ranged from 0.4 to 56 ng mL−1 with an LOD of 0.21 ng mL−1. Upon evaluating the performance of this method for the detection of trypsin in actual human urine samples, satisfactory results were finally obtained.

Graphical abstract: A ratiometric fluorescence strategy based on polyethyleneimine surface-modified carbon dots and Eosin Y for the ultrasensitive determination of protamine and trypsin

Supplementary files

Article information

Article type
Paper
Submitted
26 Nov 2021
Accepted
11 Dec 2021
First published
31 Dec 2021

Analyst, 2022,147, 677-684

A ratiometric fluorescence strategy based on polyethyleneimine surface-modified carbon dots and Eosin Y for the ultrasensitive determination of protamine and trypsin

W. Sun, F. Zhang, M. Wang, N. Wang, G. Wang and X. Su, Analyst, 2022, 147, 677 DOI: 10.1039/D1AN02138A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements