Optimal Surface Functionalization of Nanoporous Alumina Membrane for DNA Detection

2013 ◽  
Vol 631-632 ◽  
pp. 572-575 ◽  
Author(s):  
Wei Wei Ye ◽  
Mo Yang
Keyword(s):  
Dna Binding ◽  
Surface Functionalization ◽  
Dna Hybridization ◽  
Dna Detection ◽  
High Sensitivity ◽  
Label Free ◽  
Dna Immobilization ◽  
Alumina Membrane ◽  
Nanoporous Alumina ◽  
Optimal Surface

This study shows the study of optimal surface functionalization of nanoporous alumina membrane for "label-free" DNA detection. Single stranded DNA was first covalently immobilized on the nanopore walls via silane-PEG-NHS linker. The remained NHS group was hydrolyzed to form PEG layer to minimize the unspecific DNA binding during hybridization process. Optimal PEG-silane linker was achieved for better DNA immobilization efficiency. Using this optofluidic device, both ss-DNA immobilization and ds-DNA hybridization were successfully monitored via UV-Vis spectrum montoring. The nanopore size effect on DNA binding efficiency of membranes were also studied. With the increase of nanopore size, the DNA binding efficiency increased due to the increased reacted surface area. This portable optofluidic device integrated with nanoporos alumina membrane has the potential for nucleic acid in field detection in the application of food screening and environmental monitoring with high sensitivity

scholarly journals Application of Gold Nanoparticles for Electrochemical DNA Biosensor

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed Mishaal Mohammed ◽  
Ruslinda A. Rahim ◽  
Ibraheem Jaleel Ibraheem ◽  
Foo Kai Loong ◽  
Hasrul Hisham ◽  
...  
Keyword(s):  
Thin Films ◽  
Gold Nanoparticles ◽  
Dna Hybridization ◽  
Dna Detection ◽  
Dna Biosensor ◽  
Base Line ◽  
Frequency Range ◽  
Dna Immobilization ◽  
Electrochemical Dna Biosensor ◽  
Chemically Modified

An electrochemical DNA biosensor was successfully fabricated by using (3-aminopropyl)triethoxysilane (APTES) as a linker molecule combined with the gold nanoparticles (GNPs) on thermally oxidized SiO2thin films. The SiO2thin films surface was chemically modified with a mixture of APTES and GNPs for DNA detection in different time periods of 30 min, 1 hour, 2 hours, and 4 hours, respectively. The DNA immobilization and hybridization were conducted by measuring the differences of the capacitance value within the frequency range of 1 Hz to 1 MHz. The capacitance values for DNA immobilization were 160 μF, 77.8 μF, 70 μF, and 64.6 μF, respectively, with the period of time from 30 min to 4 hours. Meanwhile the capacitance values for DNA hybridization were 44 μF, 54 μF, 55 μF, and 61.5 μF, respectively. The capacitance value of bare SiO2thin film was 0.42 μF, which was set as a base line for a reference in DNA detection. The differences of the capacitance value between the DNA immobilization and hybridization revealed that the modified SiO2thin films using APTES and GNPs were successfully developed for DNA detection.

A SiO2-coated nanoporous alumina membrane for stable label-free waveguide biosensing

RSC Advances ◽  
2014 ◽  
Vol 4 (108) ◽  
pp. 62987-62995 ◽  
Author(s):  
Yong Fan ◽  
Yu Ding ◽  
Yafei Zhang ◽  
Hui Ma ◽  
Yonghong He ◽  
...  
Keyword(s):  
Optical Waveguide ◽  
Gold Layer ◽  
Label Free ◽  
Alumina Membrane ◽  
Nanoporous Alumina

Single and multimode optical waveguide detection for label-free biosensing using a PAA membrane attached to a gold layer.

Copper nanocluster as a fluorescent indicator for label-free and sensitive detection of DNA hybridization assisted with a cascade isothermal exponential amplification reaction

2018 ◽  
Vol 42 (7) ◽  
pp. 5178-5184 ◽  
Author(s):  
Xingxing Zhang ◽  
Yan Jin ◽  
Baoxin Li
Keyword(s):  
Dna Hybridization ◽  
Dna Detection ◽  
Sensitive Detection ◽  
Label Free ◽  
Fluorescent Indicator ◽  
Free Dna ◽  
Amplification Reaction

A copper nanocluster (CuNCs)-based fluorescence biosensing platform was developed for label-free DNA detection through a cascade isothermal exponential amplification reaction (EXPAR).

Nanomonitors: Electrical Immunoassays for Protein Biomarker Profiling

2008 ◽  
Vol 1106 ◽  
Author(s):  
Manish Bothara ◽  
Ravi K Reddy ◽  
Thomas Barrett ◽  
John Carruthers ◽  
Shalini Prasad
Keyword(s):  
Microelectrode Array ◽  
Performance Metrics ◽  
Point Of Care ◽  
High Sensitivity ◽  
Disease Diagnosis ◽  
Clinical Samples ◽  
Label Free ◽  
Early Disease ◽  
Alumina Membrane ◽  
Protein Biomarker

AbstractThe objective of this research is to develop a “point-of-care” device for early disease diagnosis through protein biomarker characterization. Here we present label-free, high sensitivity detection of proteins with the use of electrical immunoassays that we call Nanomonitors. The basis of the detection principle lies in the formation of an electrical double layer and its perturbations caused by proteins trapped in a nanoporous alumina membrane over a microelectrode array platform. High sensitivity and rapid detection of two inflammatory biomarkers, C-reactive protein (CRP) and Myeloperoxidase (MPO) in pure and clinical samples through label-free electrical detection were achieved. The performance metrics achieved by this device makes it suitable as a “lab-on-a-chip” device for protein biomarker profiling and hence early disease diagnosis.

In/Ex-situ Detection of HBV DNA Using Dynamic Microcantilever

2009 ◽  
Vol 74 ◽  
pp. 337-340
Author(s):  
Tae Song Kim
Keyword(s):  
Dna Binding ◽  
Resonant Frequency ◽  
Protein Detection ◽  
High Sensitivity ◽  
Hbv Dna ◽  
Ex Situ ◽  
Label Free ◽  
Frequency Shifts ◽  
Label Free Detection

The microcantilevers have emerged as a versatile biosensor, and showed excellent performance such as high sensitivity, high selectivity, and label-free detection. They have been successfully used for the detection of nucleic acids, disease marker proteins, cells, and pathogens including small molecules. So far, our group has successfully demonstrated the marker protein detection using the actuating layer (PZT)-embedded microcantilevers for the last decade. Here, we introduce in/ex-situ monitoring of the DNA binding events using performance improved actuating layer-embedded microcantilever sensors. To obtain the stable and reliable resonant frequency shifts, the microcantilevers were passivated with parylene-C film for in-situ detection and perfluorosilane (PF-Si) film for ex-situ detection. To achieve the recognition layer, the probe DNA (37-mer including T10 spacers) specific to HBV DNA was immobilized on the gold-coated microcantilever, and followed by backfilling of ethylene glycol spacer (HSC11-EG3-OH) to increase the DNA binding efficiency. After the surface treatment, the detection of HBV DNA (27-mer) was performed through two manners, in-situ and ex-situ. Target DNA in the range of 1 to 20 M and 10 nM to 5 M were applied for the in-situ and ex-situ detection respectively, and the resonant frequency shifts according to the concentration was examined quantitatively. From the results, we explained the relationship between the DNA hybridization and the nanomechanical response. In addition, we presented a hypothesis on the different tendency of in-situ and ex-situ results.

Stepping gating of ion channels on nanoelectrode via DNA hybridization for label-free DNA detection

2019 ◽  
Vol 133 ◽  
pp. 141-146 ◽  
Author(s):  
Haipei Zhao ◽  
Dekai Ye ◽  
Xiuhai Mao ◽  
Fan Li ◽  
Jiaqiang Xu ◽  
...  
Keyword(s):  
Ion Channels ◽  
Dna Hybridization ◽  
Dna Detection ◽  
Label Free ◽  
Free Dna
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