Kassandra Kisler, Brian N Kim, Xin Liu, Khajak Berberian, Qinghua Fang, Cherian J Mathai, Shubhra Gangopadhyay, Kevin D Gillis, Manfred Lindau
{"title":"Transparent Electrode Materials for Simultaneous Amperometric Detection of Exocytosis and Fluorescence Microscopy.","authors":"Kassandra Kisler, Brian N Kim, Xin Liu, Khajak Berberian, Qinghua Fang, Cherian J Mathai, Shubhra Gangopadhyay, Kevin D Gillis, Manfred Lindau","doi":"10.4236/jbnb.2012.322030","DOIUrl":"https://doi.org/10.4236/jbnb.2012.322030","url":null,"abstract":"<p><p>We have developed and tested transparent microelectrode arrays capable of simultaneous amperometric measurement of oxidizable molecules and fluorescence imaging through the electrodes. Surface patterned microelectrodes were fabricated from three different conducting materials: Indium-tin-oxide (ITO), nitrogen-doped diamond-like carbon (DLC) deposited on top of ITO, or very thin (12-17 nm) gold films on glass substrates. Chromaffin cells loaded with lysotracker green or acridine orange dye were placed atop the electrodes and vesicle fluorescence imaged with total internal reflection fluorescence (TIRF) microscopy while catecholamine release from single vesicles was measured as amperometric spikes with the surface patterned electrodes. Electrodes fabricated from all three materials were capable of detecting amperometric signals with high resolution. Unexpectedly, amperometric spikes recorded with ITO electrodes had only about half the amplitude and about half as much charge as those detected with DLC or gold electrodes, indicating that the ITO electrodes are not as sensitive as gold or DLC electrodes for measurement of quantal catecholamine release. The lower sensitivity of ITO electrodes was confirmed by chronoamperometry measurements comparing the currents in the presence of different analytes with the different electrode materials.</p>","PeriodicalId":15077,"journal":{"name":"Journal of Biomaterials and Nanobiotechnology","volume":"3 2A","pages":"243-253"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4236/jbnb.2012.322030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30697321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MEASUREMENT of Protein 53 Diffusion Coefficient in Live HeLa Cells Using Raster Image Correlation Spectroscopy (RICS).","authors":"Sungmin Hong, Ying-Nai Wang, Hirohito Yamaguchi, Harinibytaraya Sreenivasappa, Chao-Kai Chou, Pei-Hsiang Tsou, Mien-Chie Hung, Jun Kameoka","doi":"10.4236/jbnb.2010.11004","DOIUrl":"https://doi.org/10.4236/jbnb.2010.11004","url":null,"abstract":"<p><p>We have applied Raster Image Correlation Spectroscopy (RICS) technique to characterize the dynamics of protein 53 (p53) in living cells before and after the treatment with DNA damaging agents. HeLa cells expressing Green Fluorescent Protein (GFP) tagged p53 were incubated with and without DNA damaging agents, cisplatin or eptoposide, which are widely used as chemotherapeutic drugs. Then, the diffusion coefficient of GFP-p53 was determined by RICS and it was significantly reduced after the drug treatment while that of the one without drug treatment was not. It is suggested that the drugs induced the interaction of p53 with either other proteins or DNA. Together, our results demonstrated that RICS is able to detect the protein dynamics which may be associated with protein-protein or protein-DNA interactions in living cells and it may be useful for the drug screening.</p>","PeriodicalId":15077,"journal":{"name":"Journal of Biomaterials and Nanobiotechnology","volume":"1 1","pages":"31-36"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3146256/pdf/nihms281029.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30045251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}