Table 1.

The responses of electrodes to 1.0 mM of H₂O₂ with cyclic voltammetry in the presence or absence of NAD⁺.

Electrode a	Peak Current (μA) b		Sensitivity (μA·mM−1·cm−2) b
	No NAD+	50 μM NAD+	No NAD+	50 μM NAD+
PEDOT(BSA)/Pt	114.3	127.1 (11.2%)	572.3	628.8 (9.9%)
AuNPs/PEDOT(BSA)/Pt	145.1	167.3 (15.3%)	786.2	871.2 (10.8%)
HRP/AuNPs/PEDOT(BSA)/Pt	132.6	188.7 (42.3%)	719.4	974.8 (35.5%)

^a: The working area for all electrodes was approximately 0.1912 cm²; ^b: The value in parentheses is the percentage increment of the peak current and sensitivity of the same electrode in response to 1.0 M of H₂O₂ in the presence of 50 μM NAD⁺ in comparison with that in the absence of NAD⁺, for regeneration to its native active form. The unexpected decline for the signal of HRP/AuNPs/PEDOT(BSA)/Pt electrode possibly resulted from the immobilization of HRP on the AuNPs, which led to the slower electron transfer (ET) from the electrode to the active center of HRP that was critical for further reduction of H₂O₂.