Low-cost CMOS-based luminescence lifetime imaging with oxygen, temperature and pH sensors

Abstract

Luminescence imaging enables spatiotemporal visualization of physical and chemical quantities, yet widespread adoption has been hindered by expensive, specialized instrumentation. Here, we present a compact platform that employs a consumer CMOS camera for versatile luminescence imaging across biomedical research, geosciences, and aerospace engineering applications. Our approach exploits the on-chip charge accumulation capability to perform multiple exposures in one frame, thereby combining the robustness of lifetime-based measurements with the superior signal quality of time-integrated detection. We demonstrate platform versatility through three applications: (i) oxygen mapping using phosphorescent platinum(II) benzoporphyrin optodes ; (ii) the first demonstration of temperature mapping in fluid using thermally-activated delayed fluorescence (TADF) nanoparticles in a laser plane, achieving ±1 °C (1$\sigma$$\sigma$) precision for single-shot single-pixel at a $500\text{µm}$$500\text{µm}$ spatial resolution and 7 Hz temporal resolution; and (iii) pH mapping through dual lifetime referencing using a combination of a fluorescent aza-BODIPY indicator and phosphorescent Egyptian blue reference material. With total costs of approximately €2,000 for the LED configuration and €4,000 for the laser configuration, our platform reduces instrumentation barriers while maintaining precision and sampling rates comparable to specialized systems. We provide open-source Python and Arduino hardware control code (Clicc - Cumulative Lifetime Imaging with CMOS-Camera) to ensure reproducibility and encourage adoption.