Research: Mechanoanalytical Chemistry

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Micro total analysis system (mTAS), a.k.a. lab-on-a-chip, integrates a variety of lab components on a chip as small as one inch square in area (see above for an actual PDMS device). In a typical lab-on-a-chip scheme, chemicals can be synthesized, purified, and analyzed on a single chip made by lithography. The technique is indispensable in the emerging fields such as genomics and proteomics, where huge sets of data are collected and analyzed, click here for a setup used in our lab.  It is also very useful in the screening processes to identify promising drug leads or optimal conditions for crystallization. The low cost and high-throughput capability make this technique ideal for sensor development. In 2014, we showed new mTAS techniques. We developed a lab-in-a-trap (LIAT) platform for lipid droplet fusion investigations (Lanmuir, 2014). Also in the same year, we innovated a new temperature jump method with millisecond temporal resolution for microanalysis and single molecular investigations (Angewandte Chemie International Edition, 2014-1).

Combining microfluidic techniques and laser tweezers, our lab is developing highly sensitive biosensors based on mechanochemical principles. In our paper that published in the Journal of the American Chemical Society in 2011, we demonstrated a first-in-class mechanochemical sensor in which Single Nucleotide Polymorphism (SNP) was detected using a single-molecule DNA template as a mechanical transducer (we called this method as Single Molecule Mechanochemical Sensing, or SMMS). Due to the single-molecule nature, this method allows to detect SNP at picomolar concentration without any amplification steps. Recently, we expanded our research efforts to DNA aptamers, a new type of receptors that can recognize ligands with affinity and specificity approaching those of antibody-antigen interactions.

In 2014, based on our innovations of mechanochemical sensing (JACS 2011 and Angew. Chem. Int. Ed. 2014-2, see publications), mechanical affinity (Rev in Analytical Chemistry 2013), kinetic topology (JACS 2012), and other concepts, we introduced a new interdisciplinary field, mechano-analytical chemistry (see Angew. Chem. Int. Ed. 2014-2), to the chemistry and single-molecule communities. In this field, various mechanochemical approaches are exploited for chemical or biochemical analyses. Due to the involvement of the mechanical force, environmental interference is minimized. In addition, the universal variable, force, is probed or manipulated for various chemical or biological processes. Please see invited reviews ("Mechanical Affinity as a New Metrics to Evaluate Binding Events", Reviews in Analytical Chemistry (2013) and "Mechanochemical Sensing: A Biomimetic Sensing Strategy", ChemPhysChem (2015)) specifying this mechanoanalytical chemistry.