Chemical Research in Chinese Universities ›› 2026, Vol. 42 ›› Issue (5): 1489-1496.doi: 10.1007/s40242-026-6130-0

• Research Articles • Previous Articles     Next Articles

Electrostatically Enhanced Single-Molecule Sensing of Aliphatic and Aromatic Polyfluorinated Carboxylic Acids Isomers Using A260K Aerolysin Nanopore

LI Pufeng1, LI Hong-Shuang1, ZHAO Xian1, XIE Xueying1, DING Ran1, JIANG Jiale1, LIU Kexian1, ZUO Jiaqi2, QIU Kaipei1,3,4   

  1. 1. Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, Ministry of Ecology and Environment, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China;
    2. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, P. R. China;
    3. Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P. R. China;
    4. State Key Laboratory of Coal Liquification, Gasification and Utilization with High Efficiency and Low Carbon Technology, School of Energy, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2026-06-05 Accepted:2026-07-15 Online:2026-10-01 Published:2026-09-24
  • Supported by:
    This work was supported by the National Key R&D Program of China (No. 2023YFC3008803), the National Natural Science Foundation of China (Nos. 21972041, 22006037), and the Natural Science Foundation of Shanghai Municipality, China (No. 23ZR1416300).

Abstract: Per- and polyfluoroalkyl carboxylic acids (PFCA) are persistent organic pollutants with complex structures and strong biological toxicity. Single-molecule sensing using Aerolysin (Ael) nanopore and cationic probe enables standard-free quantification of PFCA homologues, but its identification performance is limited by the relatively short analyte dwell time in wild type (WT) Ael. Herein, we engineered the nanopore sensing interface by introducing lysine (K) and arginine (R) at three sites near the trans exit barrier of Ael (T240, E258, and A260) to prolong analyte dwell time and enhance resolution. All-atom molecular dynamics simulation revealed that the electrostatic potentials at trans exit shifted from negative (WT) to strong positive for all mutants. The K-substitutions significantly enhanced the signal difference among analytes, as experimentally validated by two aliphatic isomers. In particular, A260K exhibited the most superior sensing capability: dwell time was increased by 50-fold and the sigma of blockade was reduced by 80%, leading to nearly 30-fold improvement in resolutions compared to WT Ael. Further evaluation with seven aromatic PFCA isomers showed that the identification accuracy increased from 57.71% for WT Ael to 91.58% for A260K, with the aid of multi-feature classification. This study provides a new strategy towards comprehensive standard-free detection of PFCA.

Key words: Per- and polyfluorinated carboxylic acid, Engineered nanopore, Machine learning, Isomer