Research 

Nobel Laureate Wolfgang Pauli once said: “God created the bulk; the devil invented surfaces”. Our group is fascinated by chemistry happening at the interface. Surfaces or interfaces are integral parts of heterogeneous systems. It is the outermost layer of molecules or atoms in a medium or in between two media. The physical, electronic, and optical properties of interfaces or molecules at the interface are markedly different than that of the bulk medium because of the inherent asymmetry present at the interface. Because of this, many interesting and important chemical and physiological processes occur at surfaces or interfaces. Ions, enzymes, or protein transport through the cell membrane, adsorption-desorption and transport of molecules at chromatographic surfaces during separations, absorption-desorption of atmospheric gases and particles in clouds, heterogeneous catalysis are only a few of the examples where surfaces play a key role. In going from bulk to the surface, symmetry is broken which makes the surface heterogeneous and more reactive than the bulk.

The Dutta Lab brings together spectroscopy and microscopy to probe the nanoscale physical chemistry of molecules at interfaces, with the aim of addressing consequential questions in analytical, environmental, and materials science. 

Currently, we are working on the following projects.

Environmental & Analytical Sciences:

Plastic pollution is a global concern and it is evident from recent literature that micron and nano-sized plastic materials are present almost everywhere. It is challenging to quantify how much plastic is present in the environment and how these tiny particles can affect our lives. Recent studies suggest that microplastics (size ~1-10 microns) can influence marine organisms in various ways. As nanoplastics (size < 1 micron) have a higher surface-to-volume ratio, nanoplastics can have more detrimental effects on living systems. As nanoplastics could be heterogeneous both in their chemical and morphological properties, quantification of specific effects is necessary to understand system-specific effects on living systems.

We bring our expertise in interfacial physical chemistry to this urgent problem. Using model membrane systems, single-particle tracking, and vibrational spectroscopy, we investigate how nanoplastic particles of different chemical compositions and surface properties interact with lipid membranes and other biologically relevant interfaces. We are particularly interested in how these particles move, adsorb, and alter the physical properties of the surfaces they encounter, questions that are essential for understanding their biological impact and environmental fate. 

Molecular behavior at interfaces:

Our most foundational interest is in understanding how molecules behave when they are confined to, or interacting with a surface. The physical, electronic, and optical properties of molecules at interfaces differ substantially from their bulk counterparts, and we seek to understand the "why" and the "how". This includes questions of molecular orientation, surface-bound conformations, and the way interfacial asymmetry shapes chemical reactivity and recognition. Vibrational spectroscopy methods, including vibrational sum frequency generation, and in-situ Raman spectroscopy are central tools in this effort.

Materials:

Movement of molecules and particles through complex, confined, or heterogeneous environments is central to a wide range of natural and engineered systems. We investigate how transport unfolds at the nanoscale, how things move, adsorb, dwell, or pass through using single-particle tracking and superresolution microscopy. A particular focus is on anomalous and heterogeneous transport behavior, where the nanoscale details of surface interactions govern macroscopic outcomes. Understanding transport at this scale has broad implications for separations, drug delivery, sensing, and catalysis.