one finds that as the absolute quantity of both Ag and NH2-SBA-15 in the modifier decreases (compositions C1 to C4), the sensitivity of the sensor increases. At C5, the response becomes highly non-linear. The inset in Fig. 4 compares the sensitivity in presence of NH2-SBA-15, without and with AgNPs.1 It shows that, as NH2-SBA-15 content (without AgNPs) increases, the sensitivity decreases, suggesting its electrically non-conductive nature (Fig. S4). In contrast, the sensitivity increased drastically with addition of AgNPs. This enhancement is due to excellent electrical conductivity of AgNPs present in the modifier. However, with increase in Ag content (from C4 to C1), NH2-SBA-15 content also increases, which is likely to decreases the effective surface area of the electrode and hence, the sensitivity.