Nanochannels Photoelectrochemical Biosensor

Transcription

1 Supporting Information Nanochannels Photoelectrochemical Biosensor Nan Zhang 1,a, Yi-Fan Ruan 1,a, Li-Bin Zhang 1, Wei-Wei Zhao 1, 2 *, Jing-Juan Xu 1 * and Hong-Yuan Chen 1 * 1 State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu , China 2 Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States a. These authors contribute equally. * addresses: zww@nju.edu.cn; zww@stanford.edu; xujj@nju.edu.cn; hychen@nju.edu.cn This material includes: Figure S1 XRD of the Cu film before and after annealing at varying temperatures. Figure S2 Photograph of the Cu x O NPIs photocathode before and after annealing at 450 for 4 h in tube furnace. Figure S3 The energy levels of Cu x O NPIs as compared to the ROS-formation and O 2 /H 2 O potentials. Figure S4 Photocurrent stability of the Cu x O NPIs photocathode. Figure S5 Linear sweep photovoltammograms of Cu x O NPIs photocathode. Figure S6 The specific ALP catalyzed BCP reaction. Figure S7 SEM (EDX) characterization of the AAO membrane before and after 25 U L -1 ALP catalyzed BCP reaction. Figure S8 Color intensity of the AAO membrane in blue channel after BCP reaction in the presence of different ALP activity. Figure S9 SEM images of the AAO membrane with diameters of 90 nm and 280 nm before and after BCP reaction in the presence of 40 U L -1 ALP. Table S1 Element proportion change before and after ALP catalyzed BCP reaction. Table S2 ALP activity determination in real sample. S 1

2 Figure S1. XRD patterns of the Cu film before and after annealing at 150, 250, 350, 450, 550 for 4 h, respectively. Figure S2. Photograph of the Cu x O NPIs photocathode before (a) and after (b) annealing at 450 for 4 h in tube furnace. XRD patterns demonstrated in Figure S1 indicated the composition of the photocathode before and after annealing process. Well defined peaks at 42.7, 50.3 and 74.1 corresponded to diffractions from the (111), (200), and (220) planes of copper (JCPDS card number ), showing the formation of Cu via electrodeposition. The following annealing process caused a series of changes in composition of the electrode. Annealing at 150 did not make obvious difference in the composition of the electrode, while after annealing at 250, peaks belonged to Cu 2 O (JCPDS card number ) started to show. The Cu 2 O peaks (29.6, 36.4, 42.3, 61.3, 73.5 ) became more distinct when the annealing temperature raised to 350, indicating the major constituent had turned into Cu 2 O, meanwhile a few weak CuO peaks appeared (JCPDS card S 2

3 number ), implying the existence of CuO phase. Leading composition continued to transform at 450, where 13 peaks were found to be characteristic diffractions of CuO and only 2 peaks belonged to Cu 2 O left. Finally, the complex turned into CuO completely at 550. These observations revealed the temperature-dependent oxidation process of electrodeposited Cu film, namely higher temperature promoting the conversion of Cu to Cu 2 O and then CuO by reacting with diffused oxygen, which also caused a visible change of the originally reddish orange colored electrode to an ash black colored one, depicted in Figure S2. Figure S3. The energy levels of Cu x O NPIs as compared to the ROS-formation and O 2 /H 2 O potentials (ph= 8.0). Figure S4. Photocurrent stability of the Cu x O NPIs photocathode. S 3

4 Figure S5. Linear sweep photovoltammograms of Cu x O NPIs photocathode. As demonstrated in Figure S4 and Figure S5, following the onset and offset of irradiation, stable cathodic photocurrents was observed in the air-saturated Tris-HCl solution (10 mm, ph 8.0), and the photocurrent is anti-dependent with the bias potential, as a characteristic of p-type semiconductors. Figure S6. The specific ALP catalyzed BCP reaction. Table S1. Element proportion change before and after ALP catalyzed BCP reaction Element Before BCP reaction After BCP reaction Wt% At% Wt% At% C K N K O K Al K Cl K Br K S 4

5 Figure S7. SEM (EDX) characterization of the AAO membrane before (a) and after (b) 25 U L -1 ALP catalyzed BCP reaction; the scale bars equaled to 200 nm. In the enzyme catalyzed deposition reaction, soluble BCIP and NBT turned into insoluble dehydroindigo product and NBT diformazan, which accumulated on the surface and inside channels of AAO. This process caused element proportion changes on AAO surface, since elements such as C, N, Cl and Br were brought in through the reaction (illustrated in Figure S6). As shown in Table S1 and Figure S7, a significant increase of 12.78% to 36.23% in C element was observed, and the content of N, Cl, Br also got increment in varying degrees. This revealed the successful occurrence of BCP reaction, and further implied an enzyme activity retention after confinement onto AAO. Figure S8. Color intensity of the AAO membrane in blue channel after BCP reaction in the presence of different ALP activity, 5, 10, 25, 40 U L -1 respectively. As shown in Figure S8, a colorimetric analyzing method was simultaneously built taking the color intensity as an index, which could be quantified in blue channel by its photograph with the help of Adobe Photoshop software. A linear correlation between the color value of blue channel and the logarithm of ALP activity from 5.0 to 40.0 U L -1, and the linear equation was I color value = log (C ALP, U L -1 ) , with a correlation coefficient R = S 5

6 Figure S9. SEM images of the AAO membrane with a diameter of (a, b) 90 nm and (c, d) 280 nm after BCP reaction in the presence of 40 U L -1 ALP. All the scale bars equal to 200 nm. A comparison between the AAO films with different pore size (90 nm and 280 nm) was shown in Figure S9. After BCP reaction catalyzed by the same amount of ALP, particle-shape precipitation was formed on the surface and inside the channels of both the films; however, more efficient blockage was obtained by the film in diameter of 90 nm, which was chosen in the following experiments. Table S2. ALP activity determination in real sample Average Determined Average content Determined content in content Added content Photocurrent in content by (U L -1 ) (10-7 diluted in A) diluted ALP kit serum serum (U L -1 serum ) (U L -1 (U L -1 (U L -1 ) ) ) Deviation % Healthy human serum sample was determined by diluting 100 times with Tris-HCl solution (10 mm, ph 8.0) and adding different concentration of ALP (0, 2, 5 U L -1 ). According to the calibration curve, the ALP activity in the sample was found to be 97 U L -1 and was coherent with the results tested by a ALP kit (93 U L -1 ), indicating the potential for real samples of the proposed method, shown in Table S2. S 6