o Letters 33)The zeta potential of the nanobeads was measured using PALS Zeta Potential Analyzer(Brookhaven Instruments). An averaged potential of-59* ll mv from 6 runs was obtained. (34) Embryonic chicken cardiomyocytes were cultured using published protocols on thin PDMS films. 2, Device chips were ncubated with lipid vesicles of 1, 2-dimyristoyl-sn-ghy holine(DMPC, Avanti Polar Lipids Inc ) containing 1% 1-myristoyl glycero-3-Phosphocholine(NBD-lipid, Avanti Polar Lipids Inc )as fluorescent reporter to form lipid bilayers over the nanowire surface, using a procedure described earlier. The cell recording measurements were carried out in Tyrode solution(Sigma Aldrich) at 35C.The devices were forward biased at 1.0V, and the current was converted to oltage with a current preamplifier(Model 1211, DL Instruments)at nsitivity of 10- A/V, before low-pass filtered(0-6 kHz, CyberAmp 380, Molecular Devices)and digitized at 20 kHz sampling rate(Axor Digi1440A, Molecular Devices). A Ag/AgCl reference electrode was used to fix the extracellular solution potential at a constant value of +0.3V in all recording experiments anipulated using a glass micropipette mounted on a micromanipulator MP285, Sutter Instrument)to control the relative position between the cells and the nanowires as previously reported. (35)Zipes, D. P; Jalife, J. Cardiac Electrophysiology: From Cell to Bedside; Saunders: Philadelphia, 2009 1716 dxdoloro/0.1021/l300256 rINgno Lett.2012,12,1711-1716(33) The zeta potential of the nanobeads was measured using PALS Zeta Potential Analyzer (Brookhaven Instruments). An averaged zeta potential of −59 ± 11 mV from 6 runs was obtained. (34) Embryonic chicken cardiomyocytes were cultured using published protocols on thin PDMS films.2,11 Device chips were incubated with lipid vesicles of 1,2-dimyristoyl-sn-glycero-3-phospho￾choline (DMPC, Avanti Polar Lipids Inc.) containing 1% 1-myristoyl- 2-{12-[(7-nitro-2−1,3-benzoxadiazol-4-yl) amino] dodecanoyl}-sn￾glycero-3-phosphocholine (NBD-lipid, Avanti Polar Lipids Inc.) as fluorescent reporter to form lipid bilayers over the nanowire surface, using a procedure described earlier.2 The cell recording measurements were carried out in Tyrode solution (Sigma Aldrich) at 35 °C. The devices were forward biased at 1.0 V, and the current was converted to voltage with a current preamplifier (Model 1211, DL Instruments) at sensitivity of 10−6 A/V, before low-pass filtered (0−6 kHz, CyberAmp 380, Molecular Devices) and digitized at 20 kHz sampling rate (Axon Digi1440A, Molecular Devices). A Ag/AgCl reference electrode was used to fix the extracellular solution potential at a constant value of +0.3 V in all recording experiments.2,11 The PDMS/cell sheets were manipulated using a glass micropipette mounted on a micromanipulator (MP285, Sutter Instrument) to control the relative position between the cells and the nanowires as previously reported.2,11 (35) Zipes, D. P.; Jalife, J. Cardiac Electrophysiology: From Cell to Bedside; Saunders: Philadelphia, 2009. Nano Letters Letter 1716 dx.doi.org/10.1021/nl300256r | Nano Lett. 2012, 12, 1711−1716