Electrochemical experiments GDC-0449 in vitro were carried out with a CHI-660B electrochemical workstation (Shanghai, China). Measurements were performed at least three times on a glassy carbon

electrode (GCE). A conventional three-electrode system was employed, comprising a GCE (3-mm diameter) as the working electrode, a platinum wire as the auxiliary electrode, and an Ag/AgCl (saturated KCl) as the reference electrode. Voltammetric responses were recorded in 50 ml of substrate solutions prepared in PBS buffer solution. First, the modified electrode was activated by several successive voltammetric cycles from -0.20 to 0.80 V. Second, cycle voltammograms (CVs) at the rate of 50 mV · s-1 were carried out from -0.20 to 0.80 V after subtracting the background. Finally, the GCE was regenerated by 10 successive cyclic voltammetric sweeps in the blank solution. After several measurements, the GCE should be repolished. All the electrochemical measurements were carried out at room temperature. Preparation of SmBO3 nanocrystals Precursor-laminated SmBO3 multilayers were synthesized by solid-state-hydrothermal method. In a typical synthesis, 0.6 mmol Sm2O3, 0.72 mmol H3BO3, 14 ml deionized

water are mixed in a 20-ml-capacity Teflon-lined autoclave. The autoclave is sealed and maintained at 200°C constantly for 36 h and then cooled to room temperature naturally. The precipitation is centrifuged and washed with deionized water several times. Finally, as-obtained check details products are dried under vacuum at 60°C for 4 h. We propose that the formation processes of SmBO3 in the solid-state-hydrothermal system at 200°C can be assigned to two stages: Sm2O3 is first transformed into hydroxide, Sm(OH)3, then the hydroxide

interacts with H3BO3 to form products. The formation reactions of SmBO3 are proposed and shown in Figure 1. Figure 1 Formation mechanism of SmBO 3 in the S-S-H route. Immobilization of laccase on SmBO3 nanocrystals The SmBO3 multilayers were employed as carriers for the immobilization however of laccase, and the laccase was immobilized on these materials by the physical adsorption method. In a typical procedure, 100 mg of SmBO3 support was suspended in 10 ml of phosphate buffer (pH = 7.0) containing a certain amount of laccase (about 20 mg). The mixture of the supports and laccase solution was slowly stirred at room temperature for 12 h. Subsequently, the laccase immobilized on SmBO3 was separated by a centrifuge. Then the samples were washed with 10 ml of buffer solution by shaking for 5 min and separated quickly using a centrifuge. The washing procedure was repeated several times until no protein was detected in the supernatant. Finally, the laccase immobilized by SmBO3 were stored at 4°C before using. The percentage of the immobilized laccase on the SmBO3 samples is in the range of 10.7% ~ 15.2%.