Bismuth triggered selective colorimetric naked-eye detection for oxalate ions based on bromopyrogallol red that works as a molecular keypad lock

ABSTRACT

A novel colorimetric probe based on the bromopyrogallol red (BPR) for the sequential detection of Bi³⁺ and C₂O₄²⁻ was designed. The presence of Bi³⁺ led to a distinct naked-eye colour change in DMSO/H₂O (1:3, v/v) media. The detection limit of BPR for Bi³⁺ was down to nanomolar concentration (1.17 nmol L⁻¹). Also, the sensing ability of BPR for Bi³⁺ was successfully carried out in bismuth tablet and urine sample. Moreover, the resulting BPR-Bi³⁺ complex acted as an efficient colorimetric chemosensor for C₂O₄²⁻ via a colour change. Therefore, chemosensor BPR-Bi³⁺ can illustrate the ability to determine C₂O₄^2- up to 0.15 µmol L⁻¹, selectively. Notably, the absorbance changes of BPR upon the addition of Bi³⁺ and C₂O₄²⁻ were utilised as AND and NAND logic gates operating at the molecular level with Bi³⁺and C₂O₄²⁻ as chemical inputs and the absorbance signal as the output. The chemical inputs of Bi³⁺ and C₂O₄^2- in a sequential system produce an output which mimics the operation of a security keypad lock. This study provides a practical application for the sensing of C₂O₄²⁻ ions in vegetable and urine samples by the construction of the supramolecular system.

KEYWORDS:

• Colorimetric chemosensor
• naked-eye detection
• bromopyrogallol red
• bismuth(III) recognition
• oxalate recognition
• keypad lock

Acknowledgments

The authors wish to acknowledge the support of this work by Payame Noor University Research council.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplementary data for this article can be accessed here.

Additional information

Funding

The authors wish to acknowledge the support of this work by Shiraz Payame Noor University Research council with grant IDs d/7/47416 and Layout code 3146.