Fig. 4

I-V curves of the sensor under different amounts of human sweat in the dark (a) and bright (b) fields, respectively. c Conductive currents under dark and light condition are shown to directly correlate with sweat volume, underscoring the possibility of quantitative analysis of sweat monitoring. The corresponding regression curve was given to predict the volume of sweat by the current of the sensor. d Long-term stability of the CdSSe nanowire-chip sensor