Fig. 8: Sensing performance benchmark.

a Normalized Sensitivity S_N of the organic electrochemical transistor complementary amplifier compared with the theoretical limit for ion detection over 5 orders of magnitude. The S_N for the complementary OECT amplifier is equal to [1414,1904,1990,2344] mV V⁻¹ dec⁻¹ when c_min is equal to [5.4 × 10⁻⁴ 5.4 × 10⁻³ 5.4 × 10⁻² 5.4 × 10⁻¹] M, respectively, while the theoretical fundamental limit is equal to 200 mV V⁻¹ dec⁻¹. b Comparison between the normalized sensitivity and sensing range of the proposed OECT complementary amplifier with state-of-the-art ion sensors. It is worth to note that the S_N is obtained as mV⁻¹ V⁻¹ dec⁻¹ when the output of the ion sensor is expressed as a voltage, while it is obtained as µA⁻¹ mA⁻¹ V when the output is a current. In both cases it yields 10⁻³ dec⁻¹.