We proceeded to use glasses f unctionalized with amino groups protected by a Boc terminal f unction as described in f ig 6. Figure (a) represents the deprotection of BOC groups using electrochemically generated protons by chronoamperometry f rom Naf ion protected electrodes in the presence of the ACN based electrolyte (no FAM was included in these experiments). Figure shows a microscope picture corresponding to one of the electrochemical cells. The black platinized electrodes are seen in the microscope in black. The electrodes are connected by diff usion barriers that are seen in f ig. 6 (b) in grey. The circular electrode is the WE, while the short and long arched electrodes are the RE and CE, respectively. To be sure that we generated enough protons, a pulsed voltage bias to the WE vs. the RE was maintained at 0.85V f or 1 min. Figure (c) shows the electrical bias used for the generation of acid. After the exposure to this pulse, the glass was removed f rom the reactor and incubated with Rhodamine B isothiocyanate in DMF f or an hour to let the isothiocyanate f unction of the fluorophore react with newly Boc-deprotected amine. Figure shows the resulting image of the glass af ter the incubation. The area of the deprotected region is equivalent to the total footprint of our WE both being spots with a radius of ~150 μm. The f idelity of the f luorescence image in f ig. 6(d) to the footprint of the WE, shows the efficiency of the system to conf ine the acidity during the chronoamperometry experiments. This also supports the approximation that we have used through the article to consider the protons conf ined to the partial cell of t he WE. We compared the deprotection of electrochemically generated acid with the positive and negative controls described in the section materials and methods and SI-6. The results are shown in f ig. 6(e). The negative control shows that the deprotection was eff icient, while the comparison with the positive control yielded lower f luorescence on the glass of the electrochemically generated acid. Nevertheless, since we cannot exclude contributions f rom f luorescence areas larger than our f ield of view (due to imperf ections of the diaphragm in our microscope system) we believ e the positive control is an upper limit. The deprotection achieved by the electrochemically generated acid was quite signif icant, considering that the deprotected area had the same f ootprint of the WE. Since the surf ace area of the platinized electrodes was ~10 times the f lat area of the glass, we achieved such deprotection with ~10 molar equivalents of the