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Photothermal Detection of Individual Gold Nanoparticles: Perspectives for High‐Throughput Screening
Author(s) -
Kulzer Florian,
Laurens Niels,
Besser Jaya,
Schmidt Thomas,
Orrit Michel,
Spaink Herman P.
Publication year - 2008
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200800127
Subject(s) - photothermal therapy , photobleaching , colloidal gold , nanotechnology , detection limit , materials science , nanoparticle , throughput , volume (thermodynamics) , optics , fluorescence , computer science , chemistry , chromatography , physics , telecommunications , quantum mechanics , wireless
We use photothermal microscopy to detect and image individual gold nanoparticles that are either embedded in a polymer film or immobilized in an aqueous environment. Reducing the numerical aperture of the detection optics allows us to achieve a 200‐fold‐enlarged detection volume while still retaining sufficient detectivity. We characterize the capabilities of this approach for the detection of gold colloids with a diameter of 20 nm, with emphasis on practical aspects that are important for high‐throughput‐screening applications. The extended detection volume in combination with the stability of the photothermal signal are major advantages compared to fluorescence‐based approaches, which are limited by photoblinking and photobleaching. Careful consideration is given to the trade‐off between the maximum increase in local temperature that can be tolerated by a biological specimen and the minimum integration time needed to reliably determine whether a given volume contains a target species. We find that our approach has the potential to increase the detection‐limited flow rate (i.e. the limit given by the detection volume divided by the minimum detection time) by two to three orders of magnitude.