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Caption : fig. s1 schematic representation of (1) the formation of gold nanoparticles by the interaction of hydrogen tetrachloroaurate (haucl4) and sodium sulfate (na2so4); (2) the formation of cysteine-modified gold nanoparticles via au-thiol group (sh) interaction; (3) the immobilization of aptamer on l-cysteine modified gold nanoparticles via edc/nhs interaction. 

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Caption : fig. s2 nyquist plots of 5 mm [fe (cn)6]4-/3- redox couple in pbs, ph 7.4, for bare spce (curve a), aunps /spce(curve b), l-cysteine/ aunps /spce (curve c), and aptamer/ l-cysteine/ aunps/ spce (curve d) using a frequency range of 100000 hz - 0.1 hz, 10 point/decade and an ac voltage of 10 mv ms. inset: equivalent circuit (cpe with diffusion) ru(o[rpwd]) used to fit the frequency scans along with the impedance spectra. 

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Caption : fig. s3 optimization of hb-aptamer incubation time (2, 6, 10, 14, 18, 22 min). plot of peak current difference vs. hb incubation time obtaining from swv in the potential range of -0.2 to +0.4 with a frequency of 7 hz and an amplitude of 0.025v using 0.1 m pbs (ph 7.4) containing 5.0 mm [fe (cn)6]3-/4-.  

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Caption : fig. s4 effect of hb concentrations (3, 6, 9, 10 µg.ml-1) on the h2o2 electrocatalytic activity using amperometry measurements toward successive additions of h2o2 in 0.1m pbs (ph 7) with an applied potential of -0.4v. error bars correspond to the relative standard deviation of three independent experiments

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Caption : fig. s5 amperometric response at constant potential of -0.4 v for hb/aptamer/l-cysteine/aunps/spce in phosphate buffer with successive addition of 35 µm h2o2 (d), 100µm ascorbic acid (a), 500µm dopamine (b), 100µm glucose (c), 100µm fructose (e), and 100µm arginine (f)