Fig. 3

Performance characterization of the nanoprobes.

a Cyclic voltammogram of the nanoprobes in 1 mM Ru(NH₃)₆Cl₃/1 M KCl solution before and after FIB milling. Scan rate = 100 mV s⁻¹. b Cyclic voltammograms of the nanoprobe in 1 mM H₂O₂ solution and PBS solution. Scan rate = 100 mV s⁻¹. c Current response to varying H₂O₂ concentrations, with the corresponding calibration curve (inset). dI-V curves of the five individually prepared nanoprobes sputtered with a 100 nm layer of Pt and Ni in the range of -0.5 to 0.5 V in air. e Linear voltage dependence on temperature for the nanoprobe in 10 mM PBS, within the range of 294.15–320.15 K. f Thermoelectric sensitivity of five individually prepared nanoprobes. g Stability of the nanoprobe at 298 K in 10 mM PBS. h Sensitivity of the same nanoprobe over five days. i Temperature curves of the nanoprobe in 10 mM PBS with various additives. j Temperature variation curve caused by laser heating at the tip. k Simulated transient response of the nanoprobe when the cell temperature is 1 K higher than the nanoprobe. l Temperature variation of the nanoprobe (5 µm away from the tip) after the nanoprobe enters the cell, with the cell temperature higher than the environment by 0.5 K, 1 K, and 2 K