In environmental and analytical chemistry, the investigation of molecular aggregation can facilitate the sensing of contaminants. One such contaminant of significant concern is arsenic, a toxic metalloid widely distributed in the environment due to both natural and anthropogenic activities.1 As arsenic contamination poses severe threats to human health, there is a pressing need for advanced analytical techniques to assess its presence and behaviour comprehensively.2,3 In this seminar, we will discuss my research work, which delves into understanding the interaction of arsenic with proteins and recognizing the role of biomolecules in the fate and transport of this contaminant. Proteins, as essential components of living organisms, can influence the speciation and bioavailability of arsenic in environmental matrices. Investigating the binding mechanisms between arsenic and arsenic-specific proteins such as ArsD and ArsR enhances our comprehension of the interaction. It contributes to developing targeted strategies for its detection and remediation. This study used High-resolution Electrospray ionization Mass spectrometry, Ion mobility Mass Spectrometry and other spectroscopic techniques.
Microdroplet formation plays a significant role in Electrospray ionization. Our exploration extends into the intricate world of molecular aggregation and the distribution of molecules, such as proteins and dyes in microdroplets. Understanding the dynamics of microdroplet formation and the subsequent interactions of molecules within them provides valuable insights into the intricate physicochemical processes happening in them. The aggregation and de-aggregation of dye molecules and proteins were investigated through microscopy to obtain insights into the behaviour of molecules in microdroplets.4,5 This has been further extended to understanding the fate of molecules during microdroplet interactions.
Further, the self-aggregation of nanoclusters, also termed molecular materials, opens up a wide range of applications in sensing contaminants. Red emitting, self-assembled superstructures of cysteine-protected copper nanoclusters were found to be sensitive and selective towards arsenic in contaminated water. The sensitivity reached ultra-trace levels, and the selectivity was high towards arsenic in tap water spiked with other metal ions.
References:
(1) Mukherjee, S.; Gupte, T.; Jenifer, S. K.; Thomas, T.; Pradeep, T. Arsenic in Water: Speciation, Sources, Distribution, and Toxicology. Encyclopedia of Water. December 29, 2019, pp 1–17. https://doi.org/10.1002/9781119300762.wsts0053.
(2) Mukherjee, S.; Gupte, T.; Jenifer, S. K.; Thomas, T.; Pradeep, T. Arsenic in Water: Fundamentals of Measurement and Remediation. Encyclopedia of Water. December 29, 2019, pp 1–11. https://doi.org/10.1002/9781119300762.wsts0054.
(3) Mukherjee, S.; Jenifer, Kumar, S.; Nagar, A.; Pradeep, T. Concepts of Sustainability in Clean Water Technologies. In Energy Transition: Climate Action and Circularity; ACS Symposium Series; American Chemical Society, 2022; Vol. 1412, pp 16–625. https://doi.org/10.1021/bk-2022-1412.ch016.
(4) Basuri, P.; Jenifer, S. K.; Unni, K.; Manna, S.; Pradeep, T. Aggregation of Molecules Is Controlled in Microdroplets. Chem. Commun. 2022. https://doi.org/10.1039/D2CC04587G.
(5) Basuri, P.; Chakraborty, A.; Ahuja, T.; Mondal, B.; Jenifer, S. K.; Pradeep, T. Spatial Reorganization of Analytes in Charged Aqueous Microdroplets. Chem. Sci. 2022. https://doi.org/10.1039/D2SC04589C.