Direct single-molecule detection and super resolution imaging with a low-cost portable smartphone-based microscope

Detecting single molecules, which represents the ultimate level of sensitivity, is typically achieved with research-grade equipment. Here we present a low-cost, portable smartphone-based fluorescence microscope capable of detecting single-molecule fluorescence directly, i.e., without the need for any signal amplification. The setup leverages the image sensors and data handling capacity of mass-produced smartphones, it is adaptable to different smartphones and capable of detecting single molecules across the visible spectral range. We showcase this capability through single-molecule measurements on DNA origami models and super-resolution microscopy of cells by single-molecule localization microscopy. Last, we illustrate its potential as a point-of-care (POC) device by implementing a single-molecule bioassay for RNA detection. This development paves the way for innovative applications of massively distributed or personalized assays with single-molecule sensitivity in various fields such as digital bioassays, POC diagnostics, field expeditions, STEM outreach, and life science education.

How Moorfield products helped:

MiniLab 080

DNA origami sample preparation

Quartz coverslips were cut into 49 × 16.3mm substrates with a laser cutter (Q400, Trotec) and left in acetone for 1 h. Next, they were rinsed with isopropanol and soaked for 1 h in fresh isopropanol. Then, the substrates were rinsed with Milli-Q water and dried with compressed nitrogen, followed by 5 min on a hot plate at 100 °C for water desorption. Forwide-field/smartphone microscope correlation, 12 nm-thick chromium grids were created over the quartz substrate using photolithography (Direct Writing Laser system: μMLA, Heidelberg Instruments), sputtering (MiniLab 080, Moorfield Nanotechnology), and lift-off.

Open Access publication details:

Loretan, M., Barella, M., Fuchs, N. et al. Direct single-molecule detection and super-resolution imaging with a low-cost portable smartphone-based microscope. Nat Commun 16, 8937 (2025). https://doi.org/10.1038/s41467-025-63993-z