Novel Aggregation-Enhanced PEC Photosensitizer Based on Electrostatic Linkage of Ionic Liquid with Protoporphyrin IX for Ultrasensitive Detection of Molt-4 Cells.

Abstract

Nowadays, aggregation quenching of most organic photosensitizers in aqueous media seriously restricts analytical and biomedical applications of photoelectrochemical (PEC) sensors. In this work, an aggregation-enhanced PEC photosensitizer was prepared by electrostatically bonding protoporphyrin IX (PPIX) with an ionic liquid of 1-butyl-3-methylimidazole tetrafluoroborate ([BMIm][BF4]), termed as PPIX-[BMIm] for clarity. The resultant PPIX-[BMIm] showed weak photocurrent in pure dimethyl sulfoxide (DMSO, good solvent), while the PEC signals displayed a 44.1-fold enhancement in a water (poor solvent)/DMSO binary solvent with a water fraction (fw) of 90%. Such PEC-enhanced mechanism was critically studied by electrochemistry and density functional theory (DFT) calculation in some detail. Afterward, a label-free PEC cytosensor was built for ultrasensitive bioassay of acute lymphoblastic leukemia (molt-4) cells by electrodepositing Au nanoparticles (Au NPs) on the PPIX-[BMIm] aggregates and sequential assembly of protein tyrosine kinase (PTK) aptamer DNA (aptDNA). The resultant cytosensor showed a wide linear range (300 to 3 × 105 cells mL-1) with a limit of detection (LOD) as low as 63 cells mL-1. The aggregation-enhanced PEC performance offers a valuable and practical pathway for synthesis of advanced organic photosensitizer to explore its PEC applications in early diagnosis of tumors.

• Authors: Xiang Hu, Ying Wang, Xiong Zuping, Pei Song, Ai-Jun Wang, Zhaosheng Qian, Pei-Xin Yuan, Tiejun Zhao, Jiu-Ju Feng
• Journal: Analytical chemistry (Anal Chem) Vol. 94 Issue 8 Pg. 3708-3717 (03 01 2022) ISSN: 1520-6882 [Electronic] United States
• PMID: 35172575 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Ionic Liquids
• Photosensitizing Agents
• Protoporphyrins
• Gold
• protoporphyrin IX

Topics

• Biosensing Techniques
• Electrochemical Techniques
• Gold
• Ionic Liquids
• Metal Nanoparticles
• Photosensitizing Agents
• Protoporphyrins
• Static Electricity