Postdoc in Biomolecule Detection with Inverse-Designed Plasmonic Metasurfaces

In this postdoctoral project at VU Amsterdam, you will develop inverse-designed plasmonic metasurfaces for biomolecular sensing, combining optimization algorithms with electromagnetic simulations.

Postdoc in Biomolecule Detection with Inverse-Designed Plasmonic Metasurfaces

Your function

Sensitive detection of biomolecular interactions is essential for applications ranging from medical diagnostics to environmental monitoring. In this postdoctoral project, you will develop inverse-designed plasmonic metasurfaces for biomolecular sensing, combining optimization algorithms with electromagnetic simulations. The goal is to create compact optical sensors capable of detecting molecular binding events with high sensitivity using simple optical components such as LEDs, photodiodes, or cameras.

This project is part of the BIND project (Biomolecule Detection with INverse-Designed Plasmonic Metasurfaces) and aims to develop compact and low-cost alternatives to conventional surface plasmon resonance (SPR) sensors. The project will exploit plasmonic metasurfaces, periodic arrays of metallic nanoparticles whose optical resonances are highly sensitive to changes in the local refractive index induced by molecular binding. A key novelty of the project is the use of inverse design algorithms to optimize the geometry of nanoparticle arrays for maximal sensing performance. Rather than relying on intuition-driven design rules, this project will systematically explore and benchmark different optimization strategies for metasurface design (e.g. Bayesian optimization, adjoint optimization). The goal is to identify optimization strategies that are particularly effective for designing plasmonic sensors with maximal sensitivity to biomolecular binding.

The project is a collaboration between the group of dr. Andrea Baldi (Physics and Astronomy, VU Amsterdam) and the group of dr. Jeroen Kool (Chemistry and Pharmaceutical Sciences, VU Amsterdam), combining expertise in nanophotonics, nanofabrication, and biochemical sensing.

As a successful postdoctoral applicant, you will:

• develop and benchmark different optimization strategies (e.g. Bayesian optimization, adjoint optimization) coupled to numerical electromagnetic simulations (e.g. FDTD)
• model the sensing performance of plasmonic metasurfaces in response to molecular binding events, considering different sensing strategies including spectroscopic detection (tracking resonance wavelength shifts), monochromatic detection (monitoring intensity changes at a fixed wavelength), and imaging-based sensing using metasurface pixels optimized for different spectral responses
• collaborate with the PhD student in the project, who will fabricate and experimentally test the optimized metasurfaces, and with researchers in the Kool group, who will functionalize the metasurfaces and benchmark their sensing performance against conventional SPR instruments
• disseminate your research through peer-reviewed publications and presentations at international conferences
• supervise bachelor and master students

References
[1] Nugroho, F. A. A.; Bai, P.; Darmadi, I.; Castellanos, G. W.; Fritzsche, J.; Langhammer, C.; Gómez Rivas, J.; Baldi, A. Inverse Designed Plasmonic Metasurface with Parts-per-Billion Optical Hydrogen Detection. Nature Communications 2022, 13, 573 [2] Kravets, V. G.; Kabashin, A. V.; Barnes, W. L.; Grigorenko, A. N. Plasmonic Surface Lattice Resonances: A Review of Properties and Applications. Chemical Reviews 2018, 118, 5912–5951 [3] Di Santo, R.; Verdelli, F.; Niccolini, B.; Varca, S.; Gaudio, A. D.; Di Giacinto, F.; De Spirito, M.; Pea, M.; Giovine, E.; Notargiacomo, A.; Ortolani, M.; Di Gaspare, A.; Baldi, A.; Pizzolante, F.; Ciasca, G. Exploring Novel Circulating Biomarkers for Liver Cancer through Extracellular Vesicle Characterization with Infrared Spectroscopy and Plasmonics. Analytica Chimica Acta 2024, 1319, 342959 [4] Li, Z.; Prasad, C. S.; Wang, X.; Zhang, D.; Lach, R.; Naik, G. V. Balancing Detectivity and Sensitivity of Plasmonic Sensors with Surface Lattice Resonance. Nanophotonics 2023, 12, 3721–3727

Your profile

We are looking for a motivated PostDoc with strong expertise in photonics, simulations, or optimization, and a collaborative mindset.

• you have a recent PhD in physics, chemistry, materials science, nanotechnology, or a closely related field
• experience in one or more of the following areas is an advantage: nanophotonics or plasmonics, electromagnetic simulations (e.g. FDTD, COMSOL), numerical optimization or machine learning, scientific programming in Python or Matlab
• excellent verbal and written communication skills in English are essential
• curiosity, creativity, and kindness are also highly valued in our group

What do we offer?

• a salary of minimum € 3.546,00 (Scale 10) and maximum € 5.538,00 (Scale 10) gross per month, on a full-time basis. This is based on UFO profile Researcher 4. The exact salary depends on your education and experience
• your initial contract is for one year (0.8 FTE minimum). Upon positive evaluation, extension is possible

• a full time (38 hour) work week includes 232 hours of annual leave. If you choose to work 40 hours, you have 96 extra holiday leave hours on an annual basis. For part-timers, this is calculated pro rata
• 8% holiday allowance and 8.3% end-of-year bonus
• contribution to commuting expenses
• optional model for designing a personalized benefits package
• a wide range of sports facilities which staff may use at a modest charge

About us

About the PhotoConversion Materials (PCM) section

The successful applicant will be appointed as a Postdoctoral Researcher in the group of dr. Andrea Baldi, which is part of the PhotoConversion Materials (PCM) section in the department of Physics and Astronomy at the Vrije Universiteit in Amsterdam. The PCM section is a highly interdisciplinary team, working at the interface of physics, chemistry, and materials science to understand fundamental mechanisms of light-matter interaction for light-energy conversion and optical sensing. We host in-house simulation, fabrication, and spectroscopic characterization tools, with great technical research support. Additionally, we have regular access to the nanofabrication and nanocharacterization tools at the AMOLF Nanolab.

About the Department of Physics and Astronomy

The Department of Physics and Astronomy at VU Amsterdam offers an active and engaged intellectual community composed of researchers from around the world. Research is focused on four themes: (i) high-energy and gravitational physics, (ii) quantum metrology and laser applications, (iii) physics of life and health, and (iv) physics of photosynthesis and energy.