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Author Thiruvottriyur Shanmugam, S.; Trashin, S.; De Wael, K. pdf  url
doi  openurl
  Title Singlet oxygen-based photoelectrochemical detection of DNA Type A1 Journal article
  Year (down) 2022 Publication Biosensors and bioelectronics Abbreviated Journal  
  Volume 195 Issue Pages 113652  
  Keywords A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)  
  Abstract The current work, designed for the photoelectrochemical detection of DNA, evaluates light-responsive DNA probes carrying molecular photosensitizers generating singlet oxygen (1O2). We take advantage of their chromophore’s ability to produce 1O2 upon photoexcitation and subsequent photocurrent response. Type I, fluorescent and type II photosensitizers were studied using diode lasers at 406 nm blue, 532 nm green and 659 nm red lasers in the presensce and absence of a redox reporter, hydroquinone (HQ). Only type II photosensitizers (producing 1O2) resulted in a noticeable photocurrent in 1–4 nA range upon illumination, in particular, dissolved DNA probes labeled with chlorin e6 and erythrosine were found to give a well-detectable photocurrent response in the presence of HQ. Whereas, Type I photosensitizers and fluorescent chromophores generate negligible photocurrents (<0.15 nA). The analytical performance of the sensing system was evaluated using a magnetic beads-based DNA assay on disposable electrode platforms, with a focus to enhance the sensitivity and robustness of the technique in detecting complementary DNA targets. Amplified photocurrent responses in the range of 70–100 nA were obtained and detection limits of 17 pM and 10 pM were achieved using magnetic beads-captured chlorin e6 and erythrosine labeled DNA probes respectively. The presented novel photoelectrochemical detection can further be optimized and employed in applications for which enzymatic amplification such as polymerase chain reaction (PCR) is not applicable owing to their limitations and as an effective alternative to colorimetric detection when rapid detection of specific nucleic acid targets is required.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000705223300003 Publication Date 2021-09-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0956-5663 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:181796 Serial 8930  
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Author Thiruvottriyur Shanmugam, S.; Trashin, S.; De Wael, K. url  doi
openurl 
  Title Gold-sputtered microelectrodes with built-in gold reference and counter electrodes for electrochemical DNA detection Type A1 Journal article
  Year (down) 2020 Publication Analyst Abbreviated Journal Analyst  
  Volume Issue Pages  
  Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Gold-sputtered microelectrodes with built-in gold reference and counter electrodes represent a promising platform for the development of disposable DNA sensors. Pretreating gold electrode surfaces and immobilization of DNA thereon is commonly employed in biosensing applications. However, with no scientific or practical guidelines to prepare a DNA sensor using these miniature gold-sputtered microelectrodes, cleaning and immobilization steps need to be systematically optimized and updated. In this work, we present efficient cleaning and modification of miniaturized gold-sputtered microelectrodes with thiolated DNA probes for DNA detection. Additional discussions on subtleties and nuances involved at each stage of pretreating and modifying gold-sputtered microelectrodes are included to present a robust, well-founded protocol. It was evident that the insights on cleaning polycrystalline gold disk electrodes with a benchmark electrode surface for DNA sensors, cannot be transferred to clean these miniature gold-sputtered microelectrodes. Therefore, a comparison between five different cleaning protocols was made to find the optimal one for gold-sputtered microelectrodes. Additionally, two principally different immobilization techniques for gold-sputtered microelectrode modification with thiolated ssDNA were compared i.e., immobilization through passive chemisorption and potential perturbation were compared in terms of thiol-specific attachment and thiol-unspecific adsorption through nitrogenous bases. The hybridization performance of these prepared electrodes was characterized by their sensitive complementary DNA capturing ability, detected by a standard alkaline phosphatase assay. Immobilization through passive chemisorption proved to be efficient in capturing the complementary target DNA with a detection limit of 0.14 nM and sensitivity of 9.38 A M−1 cm2. In general, this work presents a comprehensive understanding of cleaning, modification and performance of gold-sputtered microelectrodes with built-in gold reference and counter electrodes for both fundamental investigations and practical DNA sensing applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000592315100017 Publication Date 2020-09-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2654 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.2 Times cited Open Access  
  Notes Approved Most recent IF: 4.2; 2020 IF: 3.885  
  Call Number UA @ admin @ c:irua:172447 Serial 6527  
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