# Diclofenac Detection via Inner‐Filter Effect Using Pyridine‐Modified Triphenylene

## TL;DR

A new sensor using modified triphenylene detects diclofenac with high selectivity and low detection limits in solution.

## Contribution

This is the first study to synthesize and apply hexa-pyridine triphenylene derivatives for diclofenac sensing.

## Key findings

- 3PY and 4PY show selectivity for diclofenac over other pharmaceuticals and hormones.
- The sensor detects diclofenac with a low limit of detection of 1.18 μM.
- The method is practical and effective in real-world samples like lake water.

## Abstract

Triphenylene derivatives 3PY (2,3,6,7,10,11‐hexa(pyridine‐3‐yl)triphenylene) and 4PY (2,3,6,7,10,11‐hexa(pyridine‐4‐yl)triphenylene) are synthesized using a Suzuki–Miyaura coupling protocol and evaluated as potent chemosensors for the detection of diclofenac in solution phase. Screening against various commonly used nonsteroidal antiinflammatory drugs and hormones demonstrates that the derivatives are selective for diclofenac. The fluorescence quenching mechanism is attributed to the inner filter effect because of the overlap between the UV–vis absorption spectrum of diclofenac and the excitation spectra of triphenylene derivatives. They can sense diclofenac with a low limit of detection of 1.18 μM, offering a simple and cost‐effective method. Moreover, the practicability and applicability of the proposed sensor are confirmed in the lake water with reliable recovery and precision.

The synthesis of hexa‐pyridine triphenylene derivatives via Suzuki‐coupling reaction and their application toward the sensing of diclofenac have been studied for the first time. The 3PY and 4PY are selective for diclofenac over the other commonly prescribed pharmaceuticals and hormones tested.© 2025 WILEY‐VCH GmbH