Uniform coating of separated nanodiamonds via thin polymer-assisted electrostatic self-assembly for thermal sensing

) and a low optical transmission loss of 1.21%. Despite the size variation of the NDs, the separated ND coating exhibits a low measurement error of 1.32 °C in thermal mapping between 27 and 80 °C. Furthermore, by steady-state thermal simulations, we show more than a sevenfold reduction in thermal spreading of the separated ND coating compared to a 100 nm thick ND film. This work offers a simple method for large-scale coating of separated NDs, paving the way for achieving non-invasive and accurate ND-based thermal sensing.