Facile Designing of a Colorimetric Plasmonic Gold Nanosensor for Selective Detection of Cysteine over Other Biothiols

Abstract

Herein, we present a facile synthesis of well dispersed gold nanoparticles (AuNPs) using 1,3‐diamino‐2‐hydroxypropane‐N,N,N’,N’‐tetraacetic acid (TA) as reducing as well as stabilizing agent. The bright red colored gold nanoparticles were found to be quite stable within the broad pH range of 4 to 10. The same detected Cysteine (Cys) selectively over other common interfering biothiols like homocysteine (Hcy), glutathione (GSH) and methionine (Met). The bright red colored AuNPs displayed bluish gray color upon their interaction with Cys within ˜20 seconds only. The ability towards assay of Cys in pharmaceutical sample made this probe further lucrative. The possibility of onspot assessement by this probe was also tested through cotton swab experiment.

Twinning as a Guiding Factor in Morphological Anisotropy of Silver Nanoparticles Stabilized Over L–DOPA: A Colorimetric Probe for Sulfide in Aqueous Medium

“…The proper control of size, shape and interparticle distances among the nanoparticles may induce a variety of miraculous properties within them . The same has led to the development of good number of protocols towards design and synthesis of nanoparticles of choice which can be useful in a variety of fields viz., chemosensing, imaging, catalysis, biomedical, photonics and electronics . It has further been pointed out that a proper control of shape rather than of size is more paying in terms of properties at nanoscale level .…”

“…Their easy synthetic protocols further provoke the nano‐scientists to investigate the various factors responsible for their growth in different shapes and sizes . These nanoparticles are very different from their bulk as well as cluster forms in terms of properties and exhibit Surface Plasmon Resonance (SPR) upon their interaction with electromagnetic radiation . The SPR of silver nanoparticles (AgNPs) stretch from the entire visible region to near infrared region (395 nm to 1300 nm) as it possesses the highest d‐sp transitions.…”

Simple and Cost-Effective Quantum Dot Chemodosimeter for Visual Detection of Biothiols in Human Blood Serum

“…Various approaches for qualitative as well as quantitative analysis of these bioanalytes have been developed, mainly based on electroanalytical techniques, , high-performance liquid chromatography (HPLC), , capillary electrophoresis separation, immunoassays based on derivatization with fluorescent/phosphorescent reagents, spectrophotometric methods, etc. , Unfortunately, all of these methods require either expensive reagents or equipment or skilled manpower to ensure reproducibility. In this context, much attention is being paid to the development of simple and cheap fluorescent probes, without compromising selectivity and sensitivity. − Nanoparticles have been proven to be an efficient substitute for organic fluorophores, particularly for developing emission “turn on/off” sensors. − Among various nanoparticles, quantum dots (QDs) are of particular interest in developing novel biosensors owing to their unique properties such as broad absorption band, emission in the visible region, photostability, etc. − Moreover, the potential of QDs to transfer electrons or holes to biologically important molecules, interacting covalently or noncovalently with their surface, can be used to tune the QD emission intensity and thus generate charge transfer-based emission “on/off” signaling. − …”