Country of origin: Singapore
Subject: Nanoscience & Nanotechnology
Matriculation year: 2017
I work on developing nanomachines to perform functions such as controllable movement and assembly of nano-objects, as well as nanomicroscopy techniques for observing the behaviour of such objects at the nanoscale.
Nanomachines first entered the public consciousness in the 1980s with the publication of a scientific paper and subsequent popular science book by K. Eric Drexler, which popularised his proposed concept of a molecular assembler -- a tiny machine that would assemble molecules by physically putting together atoms one at a time. Despite controversy over the feasibility and scientific merit of Drexler’s ideas, significant progress has since been made in research into molecular machines (as recognised with the 2016 Nobel Prize in Chemistry) and molecular assemblers (notably from David Leigh’s group).
Our research aims to demonstrate a nano-assembler that operates at a somewhat larger scale, assembling nanoparticles instead of atoms. Using a method known as DNA origami, we program custom sequences of DNA to self-assemble into pre-designed structures with nanometric precision. We can then mass-produce nano-assemblers made of parts with arbitrary 3D shapes and fine features. Our nano-assemblers could potentially be employed as synthetic enzymes that efficiently pair up gold nanoparticles into dimers. Gold nanoparticle dimers tightly focus light into localised hot spots, enhancing weak signals and thereby allowing for sensitive detection of biologically relevant molecules, for example in medical diagnostics.
As the nanomachines and nanoparticles we work with are an order of magnitude smaller than the wavelength of light, we cannot see them using conventional optical microscopy. On the other hand, higher resolution techniques such as electron microscopy can clearly resolve these nano-objects but are less suitable for observing their dynamics in solution. Instead, we use a specialised type of laser interference microscopy (interferometric scattering) which enables us to accurately track the motion of these tiny particles at high speeds.
I studied Chemistry in the National University of Singapore and then worked on holography at the Singapore University of Technology and Design before starting my MRes in Nanoscience and Nanotechnology and PhD in Physics at Cambridge.