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Caption : figure s1. (a) molecular structure of the synthesised β-cyclodextrin bound to the aptes molecule, which was used for the synthesis of the molecularly imprinted nanoporous silica nanoparticles. (b) comparison of the ftir spectra obtained in the case of pure cyclodextrin (black), pure aptes (red) and the final product (red) measurements taken with perkin elmer (us) l160000a.

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Caption : figure s2. (a) sem imaging of the exfoliated graphene oxide nanoflakes after the synthesis, revealing the typical laminated structure of graphene flakes materials. (b) uv-vis spectrum of an aqueous dispersion of the graphene flakes, revealing the standard peak of this material at 240 nm due to the π-π* plasmon, and the 310 nm shoulder due to the n-π* plasmon [7]. 

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Caption : figure s3. (a) xrd spectrum of the synthesised exfoliated graphene oxide (blue) and comparison with the spectrum obtained in the case of commercial graphite (black) and graphene flakes (red). (b) xrd spectrum of the synthesised exfoliated graphene oxide. (c) raman spectroscopy of exfoliated graphene oxide, with the typical d, g and 2d modes of graphene oxide highlighted.

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Caption : figure s4. (a) isotherms obtained for the molecularly imprinted sensing material after the synthesis onto graphene oxide by using bet. (b) estimated pore size distribution of the molecularly imprinted material here reported, indicating the adsorbed volume at each value of pore radius.

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Caption : figure s5. (a) detail of the silica nanoparticles deposited onto the graphene oxide films obtained by sem. (b) sem imaging of the silica nanoparticles onto the graphene oxide. (c) size distribution of the silica nanoparticles deposited onto the graphene oxide flakes (binned 5 nm). 

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Caption : figure s6. (a) schematic representation of the calculation of the theoretical limit of detection. here, the signal obtained after measuring the potentiometric signal of the sensing devices in simulated body fluids was recorded and used as a baseline. the intersection with the calibration point obtained after calibrating the sensors was then measured. such limit of detection was in the range of 2.5 x 10-15 m. (b) representation of a typical experiment using pulse voltammetry. initially a equilibration step is employed for 5 min, until a stable signal is obtained. after this, a current is established between the working and counter electrodes, amplifying the potentiometric signal. a final re-equilibration step is used, allowing the regeneration of the baseline signal obtained by ocp measurements. multiple currents can then be used using the same device. (c) the signal obtained after applying a 5s current pulse is shown. here, the potential is calculated as the difference between the initial and final potential obtained during the pulse. (e) electrochemical data used for the calibration of the device. (f) detail of the potentiometric changes of the sensors during the pulse amperometry. (g) comparison of the ocp response obtained in the case of templated sensors compared to the non-templated version at different concentrations. the electrochemical noise levels are indicated.