Nanodrop chemistry: Recent advances

The study of chemistry in nanodroplets and microdroplets is an emerging area that has transformed our understanding of reaction dynamics at interfaces. This field holds significant promise for applications in atmospheric chemistry, environmental science, and various industrial sectors. Nanodroplets, with their high surface-to-volume ratio, exhibit reaction mechanisms that differ fundamentally from bulk-phase reactions, primarily due to their ability to concentrate reactants at the air-liquid interface and alter redox potentials, creating conditions that enhance reaction rates. This literature mini-review explores the major advances in understanding the physicochemical properties of nanodroplets, particularly the role of interfacial phenomena in accelerating chemical reactions. Key discoveries include the spontaneous formation of hydrogen peroxide and other reactive oxygen species, which have profound implications for atmospheric and environmental chemistry. Experimental studies reveal that strong electric fields at droplet surfaces, often on the order of 107 V/cm, play a pivotal role in these reactions by altering activation energies and enabling electron transfer processes that are otherwise suppressed in bulk solutions. Furthermore, this mini-review highlights advances in the synthesis of both organic and inorganic compounds within nanodroplets, with reaction rates up to 107 times faster than in bulk, as seen in bimolecular reactions such as the reduction of dichlorophenolindophenol by ascorbic acid. Novel applications, including the conversion of carbon dioxide into formic acid and the spontaneous formation of hydrogen gas at water-oil interfaces, illustrate the broader industrial relevance of this field. Rapid protein digestion within microdroplets further demonstrates its utility in proteomics, where reaction times are significantly reduced. Overall, the unique environment of nanodroplets provides unprecedented opportunities for accelerating chemical processes, offering sustainable, green alternatives for various applications in industry, environmental remediation, and beyond. Continued research into droplet chemistry is expected to reveal new reaction mechanisms and products, potentially revolutionizing both fundamental chemical understanding and practical applications.