Bimetallic CuFe Prussian Blue Analogue Nanocubes as a Colorimetric Probe for the Quantification of Glutathione

Abstract

Label-free bimetallic CuFe Prussian blue analogue nanocubes (CuFe PBA NCs) were directly employed as colorimetric probes for the visual determination of glutathione (GSH). CuFe PBA NCs produce an absorption peak at 400 nm. In the presence of GSH, the CuFe PBA NCs were transformed into larger hollow nanospheres based on the acid-initiated Kirkendall effect, leading to the appearance of a new peak at 520 nm and a solution color change from yellow to red. Thus, the GSH-induced color changes allowed the establishment of a double-signal colorimetric assay for GSH using the ratio of absorbance at 520 and 400 nm (Δ(A₅₂₀/A₄₀₀)). Facile determination of GSH from 0.1 to 8 μM with satisfactory specificity was developed, providing a detection limit as low as 0.08 μM. Additionally, GSH concentrations exceeding 3 μM can be directly identified by the naked eye. The colorimetric assay for GSH has also been demonstrated to have application for serum analysis. Compared with conventional single-signal colorimetric determination, the ratiometric probe was demonstrated to provide good selectivity and high sensitivity.

Keywords:

• CuFe Prussian blue analogues
• double-signal colorimetric probe
• glutathione
• Kirkendall effect
• spectrophotometry
• visual detection

Disclosure statement

No potential competing interest was reported by the authors.

Additional information

Funding

The support of this work by the Foundation of 2022 Zigong Key Science and Technology Plan Project (Collaborative Innovation Category of Zigong Medical Big Data and Artificial Intelligence Research Institute) (Grant No. 2022ZCYGY17 and 2022ZCYGY22) and Open Fund of Innovation Center for Chenguang High Performance Fluorine Material, Sichuan University of Science and Engineering (Grant No. SCFY2210) is gratefully acknowledged.