After the MULTIPLY Fellowship Dr.Nikita Toropov joined the University of Exeter. Now he works with Prof.Frank Vollmer at the Vollmer Laboratory of Nano and Quantum Biosensing and he is really happy to be there. And we have good news! Now you can join this research group as a Ph.D. student!
Dr.Nikita Toropov about the Vollmer Laboratory of Nano and Quantum Biosensing:
“Lab of Nano and Quantum Biosensing is truly the place where physics meets biology, conventional and emerging photonic devices find impressive applications in biosensors leading to breakthroughs in single-molecule and single viral particle studies. For this, a background in photonics is always desirable; concomitantly our cross-disciplinary team formed of physicists, engineers, biologists, and chemists is open to new ideas bringing by new members and collaborators from all around the world. It is a unique experience to take part in this work!”
Optical studies of single molecules have led to important advances in chemistry, physics and biology. However, those discoveries are often limited by the sensitivity of the instruments. In an effort to overcome measurement noise and detection limits, researchers around the world seek ways to apply quantum optical precision measurements in single molecule studies. Quantum enhanced single molecule sensors could enable more precise studies of Life’s complexity at molecular level. They could reveal information hidden in the sensor signals.
You will establish a novel single-molecule “nanoprobing” technique by means of analysing the statistical and quantum optical properties of photons emitted from a molecule on a microcavity-based sensor. You will use the highly sensitive optical micro-interferometer together with quantum measurement techniques to study the light matter interaction in either a weak or strong coupling regime. Moreover, measurements extracting more information per photon resource will be ideally suited to study biological samples with minimal perturbation, and to probe samples for longer time periods than otherwise possible using classical light. This approach will be capable of discerning changes in the nano-environment of a molecule (pH, temperature, binding of ligand molecules) and discerning molecular conformations and states with a microsecond time resolution that were previously difficult to detect, i.e.by fluorescence lifetime imaging. In a second part of the project that will be a team effort at the Living Systems Institute, you will apply your quantum sensing techniques in bio-imaging. The goal is to develop a set of neuro-imaging techniques based on novel quantum approaches to visualise brain function.
You will undertake the development of an optoelectronic microreactor-system of a new type that combines our single-molecule sensing approach with the ability of manipulating enzyme function in real time. Controlling single-molecule reactions is becoming feasible on optoplasmonic sensors. In this emerging area of optoplasmonics, light is shrunk to the length scale of molecules to probe single-molecule reactions. The light defines the nanoscale sensing and reaction volume thereby isolating for single-molecules. In this project, you will combine the optoplasmonic sensors with an optoelectronic microreactor to control enzyme activity. You will develop an new type of optoelectronic microreactor-system that will have the dual role of a) monitoring the enzymatic reaction in real time and b) exerting control over the reaction pathway. You will use temperature as well as optical gradient forces (optical tweezers) to manipulate the enzyme activity and the reaction pathways. To achieve this goal, you will use a key component of the optoelectronic microreactor-system, a plasmonic nanoparticle that the enzyme will be attached to. You will use laser light to probe the nanoparticles plasmon resonance to detect the enzyme-substrate complex and its movements and conformational changes in real time. You will use the laser to apply optical forces on to the enzyme using the plasmonic near field enhancements. Applying very small, femtonewton (fN) forces offers the possibility of making some conformational states of the enzyme more likely than others, and this can be used to control enzymatic activity. You will use a secondary laser beam to rapidly cycle the temperature of the nanoparticle and with that implement on/off switch of the overall activity of the enzyme. In the second part of the project you will work in a larger team to apply the enzyme manipulation capabilities to DNA polymerase such as terminal deoxynucleotidyl transferase TdT in order to demonstrate a DNA ‘writer’, the de novo synthesis (‘writing’) of DNA.