To test the bactericidal performance of the hand sprayer-coated glass as a proof of concept, we performed a bacterial viability test using E. coli, a common pathogen seen on smartphones, through incubating a bacterial solution on the surface for time (12 and 24 h, respectively) before transferring to agar plates for colony counting. The hand sprayercoated glass shows a significant decrease of viability (3.14 ± 4.22%) compared to the uncoated one (100 ± 12.33%), realizing the immense bactericidal activity (Figure ). Such the activity is comparable to other bactericidal coatings in literature, as well as those commercially available (Table ). On one hand, the uncoated culture plates (insets of Figure ) show live bacteria colonies (white spots) after 12 h (i), which multiplied after 24 h (ii), indicating further bacterial proliferation; on the other hand, almost no sign of bacterial growth is seen in the hand sprayer-coated glass cultures after 12 h (iii) and becomes virtually clean after 24 h (iv). Overall, this proves the bactericidal efficacy of the hand sprayer-coated surface. To test the coating durability against swiping, a setup composed of a rubber eraser pressed down by a 100 g weight (corresponding to a pressure of 2.31 kPa) was used (Figure ). Pressurized swiping was simulated by pulling the hand sprayer-coated glass while holding the setup in place. After 100 swipes, the samples show the retained loadings of Ag and Zn decreased to 60.44, and 44.42%, respectively, while the Cu one is highly preserved to be 99.04% (Figure ). Relating to the average finger swiping pressure of 0.5 kPa 33 the projected complete removal of Ag, Zn, and Cu should occur after 940, 1,321, and 48,300 swipes, respectively. Hence, the bactericidal coating may remain for ~185 days based on the daily average swiping interactions by the public on mobile devices (2,617 swipes a day). In terms of dermal contact, the maximum amount of the metals deposited in a single coat accounts only to 0.014% (for Cu and Zn), and 0.289% (for Ag) of their respective lethal doses (in mg metal/kg body weight) which ensures safety of usage (See Supporting Information, Table ). The durable retention of the film is consistent with those of ARDcoated substrates that can resist 100 times peeling-off using adhesive tape, as well as coated stainless still resisting multiple abrasions by a rubber ball. This suggests the excellent adhesion of the ARD-based coating on the substrate regardless of the transparency level and/or thickness.