Nanochannel-Ionchannel Hybrid Device for Ultrasensitive. Monitoring of Biomolecular Recognition Events

Transcription

1 Nanochannel-Ionchannel Hybrid Device for Ultrasensitive Monitoring of Biomolecular Recognition Events Xiao-Ping Zhao, Yue Zhou, Qian-Wen Zhang, Dong-Rui Yang, Chen Wang, * Xing-Hua Xia * Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, and Key Laboratory of Biomedical Functional Materials, School of Science, China Pharmaceutical University, Nanjing, , China State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing , China * address: xhxia@nju.edu.cn; wangchen@cpu.edu.cn

2 Figure S1. FT-IR spectrum of aptamer-immobilized PAA using pure PAA membrane as the reference. Figure S2. (A) EIS of bare gold electrode (GE) (a); NH 2-TBA/GE (b); MCH/NH 2-TBA/GE (c); Thr/MCH/NH 2-TBA/GE at ph 6.3 solution (d); Thr/MCH/NH 2-TBA/GE at ph 9.0 solution (e); Thr/MCH/NH 2-TBA/GE at ph 7.4 solution (f). (B) Effect of ph on the specific binding of thrombin onto aptamer immobilized on the surface of the gold electrode. As a powerful tool for probing the different interface features, the electrochemical impedance spectroscopy (EIS) was used to confirm the stability of the formed

3 thrombin-aptamer complexes under different ph. In the Nyquist diagram, the semicircle diameter is related to the electron transfer resistance (R), while the linear part represents the diffusion process. 1 It can be seen from Figure S2A that the bare gold electrode exhibits a super small R (curve a) due to the excellent conductance of the gold electrode. After TBA was modified on the electrode surface, the R increases obviously (curve b), suggesting that TBA has been successfully attached onto the electrode. The use of an additional layer of 6-mercapto-1-hexanol (MCH) for blocking electrode surface causes a further increase in semicircle diameter (curve c). After binding with thrombin for 50 min, the modified electrode is immersed in different ph solution to measure the EIS (curve d, e, f). We find that the R increases significantly owing to the biomolecular recognition between thrombin and aptamer. The results imply that thrombin-aptamer recognition can successfully occur at the three ph solutions. Interestingly, we find that the R is maximum at ph 7.4. (Figure S2B). It has been reported that thrombin-aptamer complex is most stable in neutral than in alkaline medium and acid systems. 2 Therefore, more thrombin-aptamer bindings are expected to occur at ph 7.4 than other two ph environments.

4 Figure S3. Evolution of current at V as a function of recognition reaction time in a solution at ph 9. The thrombin concentration is nm. Figure S4. Evolution of current at +0.8 V as a function of recognition reaction time in a solution ph 6.3. The thrombin concentration is nm.

5 Figure S5. The fr value of the nanochannel-ionchannel hybrid device with different thrombin concentrations at ph 9. Figure S6. The relative ion current at +1.0 V of four modified nanochannel-ionchannel hybrid in the presence of 10 fm thrombin.

6 Table S1. Comparison of the performance of various sensing systems for the detection of thrombin Detection Detection Linear range Reference method limit Colorimetry 7.5 nm 10 nm-5μm 3 Fluorescence 8.9 pm 0.25 pm-25 nm 4 Electrochemistry 0.32 pm 1pM-30 nm 5 Chemiluminescence 0.55 pm 1pM-25 pm 6 Electrochemiluminescence 4.5 fm 10 fm to 10nM 7 Fluorescence Resonance 0.01 pm 0.05 pm-200 pm 8 Energy Transfer (FRET) Surface Plasmon Resonance 1 nm 1 nm-35nm 9 This work 0.22 fm 1fM nM REFERENCE (1) Chen, S.; Liu, P.; Su, K.; Li, X.; Qin, Z.; Xu, W.; Chen, J.; Li, C.; Qiu, J. Biosens. Bioelectron. 2018, 99, (2) Ostatná, V.; Vaisocherová, H.; Homola, J.; Hianik, T. Anal. Bioanal. Chem. 2008, 391, (3) Li L.; Liang, Y.; Zhao, Y.; Chen, Z. Sensor. Actuat. B-Chem. 2018, 262, (4) Umrao, S.; Jain, V.; Anusha.; Chakraborty, B.; Roy, R.; Sensor. Actuat. B-Chem. 2018, 267, (5) Yang, X.; Lv, J.; Yang, Z.; Yuan, R.; Chai, Y. Anal. Chem. 2017, 89,

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