Figure 1

Morphological transition and composition analysis of the sturucture on the surface of a silver NHC chip. a, The surface of Proteo®chip, a biochip with silver NHCs on a phosphor bronze plate with a round shape, was recorded by using an SEM (JSM-7001F, JEOL Ltd., Tokyo). The color of the area where sodium hypochlorite was added changed from bronze to black (green arrow) from bronze and then to white (red arrow) after laser irradiation. b, Silver NHCs were observed on the surface of the chip. c, After adding sodium hypochlorite onto the chip, structures composed of egg-shaped masses and thorns were observed on the chip surface. d, Fluff- and bridge-like components were also observed after adding a clinical serum sample obtained from a patient with Stage IIIa gastric cancer. e, Composition analysis of the surface of a silver NHC chip after adding sodium hypochlorite by using energy dispersive X-ray spectroscopy. The atomic percent of oxygen (91.91%) suggested that the chip surface mainly comprised silver superoxide under oxygen-rich conditions. Chlorite was hardly observed.