Silver oxide nano-colloid based selective colorimetric sensor for the recognition of cystine in aqueous solution

ABSTRACT

Sodium alginate modified Ag₂O (SA@Ag₂O) nano-colloid is synthesised and studied colorimetric response towards eight selected amino acids in aqueous medium at room temperature. The synthesised SA@Ag₂O nano-colloid showed a surface plasmon band at 469 nm. Distinctive colour change of the dark brown colloid to colourless is observed in the case of Cystine. Among the eight amino acids studied such as D-L- Aspartic acid, L-Glutamic acid, Glycine, Alanine, D-L Methionine, L-Cysteine, L-Cystine and L-Tyrosine. L-Cystine stands out by completely decolorising the brown colloid which can be detected by the ‘naked-eye’. This sensor selectively detects Cystine. To understand the sensing mechanism, the amino acid treated SA@Ag₂O colloids were characterised by UV, XRD, FTIR and TEM analysis. This approach offers several advantages such as simplicity, low cost and high sensitivity.

Graphical abstract

An environment friendly approach for the detection of cystine in aqueous solution using SA@Ag₂O nano-colloid

KEYWORDS:

• Amino acids
• Sensor
• colloid
• Silver oxide
• cysteine

Acknowledgments

The authors thank VIT University for providing all required facilities to carry out the experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

V. Andal

V. Andal has completed her Ph.D. from Vellore Institute of Technology Vellore, India in the year 2013. Currently, She is a Assistant Professor (S.G) in the Chemistry Division, Science and humanities Department, KCG College of Technology, Chennai, Tamil Nadu, India. Her research fields are nanomaterials, sensors and catalytic materials.

G. Bhuvaneswari

G. Bhuvaneswari has completed her Ph.D. from Indian Institute of Technology Madras, India in the year 2000. She has carried out her post doctoral research in the Department of Chemistry, University of Florida during 2001–2004. Currently, she is a Professor in the Chemistry Department and Division Leader, Materials Division, School of Advanced Sciences, VIT University, Vellore, Tamil Nadu, India. Her research fields are nanomaterials and catalytic materials.