Development of Nitro-Substituted Pyrido[1,2- a ]indole Fluorophores for Environment-Sensitive Bioimaging

Organic Letters 2026

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Authors: Jae‐Joong Kim, Jae‐Joong Kim, Taegwan Kim, Ji Soo Kang, Seunghyeon Hwang, Jinjoo Jung, Jongmin Park, Youngjun Lee, Jonghoon Kim, Jonghoon Kim
DOI: 10.1021/acs.orglett.6c00141
Cited by: 4
References: 40

Abstract

We report the design and synthesis of a novel pyrido[1,2- a ]indole fluorophore that exhibits deep-red emission (up to 660 nm), a large Stokes shift (6118 cm –1 ) in methanol, and excellent biocompatibility. Positional nitration enables systematic modulation of the photophysical properties across a series of regioisomers. Spectroscopic analyses and calculations revealed the intramolecular charge transfer (ICT) and rotation-induced quenching behavior. The fluorophores showed exceptional lipid droplet (LD) labeling capability in live-cell imaging without washing steps, indicating their potential for biomedical applications. This study demonstrates that simple nitro-group relocation on a compact heteroaromatic scaffold provide tunable, environment-sensitive fluorophores for probe development.

Fields of Study & Subjects

Luminescence and Fluorescent Materials Advanced Fluorescence Microscopy Techniques Molecular Sensors and Ion Detection

Publication details

Journal / source
Organic Letters
Publisher
American Chemical Society (ACS)
Volume
28
Issue
12
Pages
3701–3706
Publication date
18 March 2026
Language
EN