Nanogold Aggravating MEMS Cantilever Capacitance Detection Biochip

2010 ◽  
Vol 159 ◽  
pp. 429-433 ◽  
Author(s):  
Zhong Liang Deng ◽  
Yue Tao Ge ◽  
Wei Guo Guan ◽  
Nai Bo Zhang ◽  
Qi Ke Cao
Keyword(s):  
Gold Nanoparticles ◽  
Integrated Circuit ◽  
Low Cost ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Capacitive Pressure Sensor ◽  
Target Dna ◽  
Capacitance Detection ◽  
Before And After ◽  
Hybridization Reaction

A kind of array micro-electromechanical systems (MEMS) cantilever of biochip is designed, which integrated capacitive pressure sensor. Before and after hybridization reaction, by the change of capacitance value, it can measure the capacitance values through integrated circuit (IC) to judge whether the solution containing the cantilever probe genes. In order to improve the detection sensitivity, it aggravate cantilever by gold nanoparticles combining hybridization information, applying Au-S chemical bond of gold nanoparticles and dithiol HS(CH2)6SH to combine and fix DNA probes and applying target DNA marked with biotin to combine gold nanoparticles by Biotin - Streptavidin combining. The results shows that this biochip can detect biological samples fast, high throughput, low cost, high sensitivity and reliably.

Nanogold Aggravating MEMS Cantilever Piezoelectric Optical Detection Biochip

2010 ◽  
Vol 39 ◽  
pp. 198-202 ◽  
Author(s):  
Zhong Liang Deng ◽  
Yue Tao Ge ◽  
Wei Guo Guan ◽  
Nai Bo Zhang ◽  
Qi Ke Cao
Keyword(s):  
Gold Nanoparticles ◽  
Low Cost ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Optical Detector ◽  
Target Dna ◽  
Before And After ◽  
Hybridization Reaction ◽  
Piezoelectric Devices ◽  
Cantilever Probe

A kind of array micro-electromechanical systems (MEMS) cantilever of biochip is designed, which piezoelectric devices drive MEMS cantilever resonance. Before and after hybridization reaction, by the change of the resonant frequency of the cantilever, it can detect the cantilever amplitude through optical detector to judge whether the solution containing the cantilever probe genes. In order to improve detection sensitivity, it aggravate cantilever by gold nanoparticles combining hybridization information, applying Au-S chemical bond of gold nanoparticles and dithiol HS(CH2)6SH to combine and fix DNA probe and applying target DNA marked with biotin to combine gold nanoparticles by Biotin - Streptavidin combining. The results shows that this biochip can detect biological samples fast, high throughput, low cost, high sensitivity and reliably.

Simulation of Gold Nanoparticles Aggravating MEMS Cantilever Optical Static Detection Biochip

2013 ◽  
Vol 694-697 ◽  
pp. 966-970 ◽  
Author(s):  
Yue Tao Ge ◽  
Xiao Tong Yin
Keyword(s):  
Gold Nanoparticles ◽  
Low Cost ◽  
Mechanical Systems ◽  
Side Wall ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Gene Detection ◽  
Micro Electro Mechanical Systems ◽  
Target Dna ◽  
Static Detection

A kind of gene detection biochip model based on biological micro electro mechanical systems (BioMEMS) technology and micro optical electro mechanical systems (MOEMS) technology is designed and simulated. In order to detect whether there are nucleic acid components in the testing samples, the biochip in this study issues horizontal light by laser, then receives and reads the deformation signals of MEMS cantilever by optical detector. The MEMS optical reflecting system can amplify MEMS cantilever deformation signal 22 times by micro reflectors which are set on the side wall of the cantilever free end. In order to improve optical detection sensitivity, gold nanoparticles (GNPs) which are combined with hybridization information is taken to aggravate MEMS cantilever, and employ Au - S chemical bond of GNPs and dithiol HS(CH2)6SH to combine and fix DNA probe, and then employ target DNA which is marked with biotin to combine GNPs by Biotin - Streptavidin combining. The simulation results show that this biochip can detect biological samples fast, high throughput, low cost, high sensitivity and reliably.

Flexible Pressure Sensor Based on Photo Paper-Molded Micro-Structural AgNWs/PDMS Electrode

2015 ◽  
Vol 748 ◽  
pp. 1-4 ◽  
Author(s):  
Li Xin Mo ◽  
Yu Qun Hou ◽  
Qing Bin Zhai ◽  
Wen Guan Zhang ◽  
Lu Hai Li
Keyword(s):  
Pressure Sensor ◽  
Silver Nanowires ◽  
Low Cost ◽  
Flexible Substrate ◽  
High Sensitivity ◽  
Low Energy ◽  
Capacitive Pressure Sensor ◽  
Micro Structure ◽  
Energy Consuming ◽  
Flexible Pressure Sensor

The novel flexible pressure sensor with skin-like stretchability and sensibility has attracted tremendous attention in academic and industrial world in recent years. And it also has demonstrated great potential in the applications of electronic skin and wearable devices. It is significant and challenging to develop a highly sensitive flexible pressure sensor with a simple, low energy consuming and low cost method. In this paper, the silver nanowires (AgNWs) as electrode material were synthesized by polyol process. The polydimethylsiloxane (PDMS) was chosen as a flexible substrate and polyimide (PI) film as dielectric layer. The AgNWs based electrode was prepared in two methods. One is coating the AgNWs on photographic paper followed by in situ PDMS curing. Another one is suction filtration of the AgNWs suspension followed by glass slide transfer and PDMS curing. Then the capacitive pressure sensor was packaged in a sandwich structure with two face to face electrodes and a PI film in the middle. The sensitivity of the sensor as well as the micro-structure of the electrodes was compared and studied. The results indicate that the roughness of the electrode based on AgNWs/PDMS micro-structure plays an important role in the sensitivity of sensor. The as-prepared flexible pressure sensor demonstrates high sensitivity of 0.65kPa-1. In addition, the fabrication method is simple, low energy consuming and low cost, which has great potential in the detection of pulse, heart rate, sound vibration and other tiny pressure.

scholarly journals Assessing the Role of Uric Acid as a Predictor of Preeclampsia

2022 ◽  
Vol 12 ◽  
Author(s):  
Ana I. Corominas ◽  
Yollyseth Medina ◽  
Silvia Balconi ◽  
Roberto Casale ◽  
Mariana Farina ◽  
...  
Keyword(s):  
Uric Acid ◽  
Serum Uric Acid ◽  
Predictive Value ◽  
Gestational Hypertension ◽  
Low Cost ◽  
High Sensitivity ◽  
Use Of Resources ◽  
Before And After ◽  
High Negative Predictive Value ◽  
Group A

We assessed the diagnostic utility of uric acid for the prediction of preeclampsia. An observational prospective approach was carried out during 2014. Preeclamptic women were classified into 4 groups accordingly to the onset of preeclampsia and the presence of intrauterine growth restriction (IUGR). Serum uric acid levels, urea, and creatinine were measured. Receiver operating curves (ROC) of the uric acid levels ratio (UAr) between a dosage before and after the 20th week of gestation were performed. One thousand two hundred and ninety-third pregnant women were enrolled in this study. Eight hundred ten had non-complicated pregnancies, 40 preeclampsia, 33 gestational hypertension, and 20 IUGR without preeclampsia. Uric acid significantly raised after 20 weeks of gestation in women who develop preeclampsia before 34 weeks (Group A) or in those who develop preeclampsia after 37 weeks associated with IUGR (Group C). In women who develop preeclampsia after 34 weeks without IUGR (Groups B and D), uric acid increased after the 30th week of gestation. In all groups, UAr was greater than 1.5. In gestational hypertension, UAr was superior to 1.5 toward the end of gestation, while in IUGR without preeclampsia, the behavior of serum uric acid was similar to non-complicated pregnancies. In all cases, urea and creatinine showed normal values, confirming that patients had no renal compromise. ROC area was 0.918 [95% confidence interval (CI): 0.858–0.979) for the preeclampsia group and 0.955 (95% CI: 0.908–1.000) for Group A. UAr at a cut-off point ≥1.5 had a very low positive predictive value, but a high negative predictive value of 99.5% for preeclampsia and it reached 100% for Group A. Thus, a UAr less than 1.5 may be a helpful parameter with a strong exclusion value and high sensitivity for those women who are not expected to develop preeclampsia. Additionally, this low-cost test would allow for better use of resources in developing countries.

scholarly journals Colorimetric Sensing with Gold Nanoparticles on Electrowetting-Based Digital Microfluidics

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1423
Author(s):  
Zhen Gu ◽  
Jing-Jing Luo ◽  
Le-Wei Ding ◽  
Bing-Yong Yan ◽  
Jia-Le Zhou ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Low Cost ◽  
Digital Microfluidics ◽  
High Sensitivity ◽  
Bulk Solution ◽  
Label Free ◽  
Colorimetric Sensing ◽  
Wide Range ◽  
The Stability ◽  
Digital Microfluidic

Digital microfluidic (DMF) has been a unique tool for manipulating micro-droplets with high flexibility and accuracy. To extend the application of DMF for automatic and in-site detection, it is promising to introduce colorimetric sensing based on gold nanoparticles (AuNPs), which have advantages including high sensitivity, label-free, biocompatibility, and easy surface modification. However, there is still a lack of studies for investigating the movement and stability of AuNPs for in-site detection on the electrowetting-based digital microfluidics. Herein, to demonstrate the ability of DMF for colorimetric sensing with AuNPs, we investigated the electrowetting property of the AuNPs droplets on the hydrophobic interface of the DMF chip and examined the stability of the AuNPs on DMF as well as the influence of evaporation to the colorimetric sensing. As a result, we found that the electrowetting of AuNPs fits to a modified Young–Lippmann equation, which suggests that a higher voltage is required to actuate AuNPs droplets compared with actuating water droplets. Moreover, the stability of AuNPs was maintained during the processing of electrowetting. We also proved that the evaporation of droplets has a limited influence on the detections that last several minutes. Finally, a model experiment for the detection of Hg2+ was carried out with similar results to the detections in bulk solution. The proposed method can be further extended to a wide range of AuNPs-based detection for label-free, automatic, and low-cost detection of small molecules, biomarkers, and metal ions.

scholarly journals Regenerable Bead-Based Microfluidic Device with integrated THIN-Film Photodiodes for Real Time Monitoring of DNA Detection

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 953
Author(s):  
Catarina R. F. Caneira ◽  
Denis R. Santos ◽  
Virginia Chu ◽  
João P. Conde
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Microfluidic Device ◽  
Low Cost ◽  
High Sensitivity ◽  
Significant Loss ◽  
Real Time Monitoring ◽  
Target Dna ◽  
On Chip ◽  
Biosensing System

Nanoporous microbead-based microfluidic systems for biosensing applications allow enhanced sensitivities, while being low cost and amenable for miniaturization. The regeneration of the microfluidic biosensing system results in a further decrease in costs while the integration of on-chip signal transduction enhances portability. Here, we present a regenerable bead-based microfluidic device, with integrated thin-film photodiodes, for real-time monitoring of molecular recognition between a target DNA and complementary DNA (cDNA). High-sensitivity assay cycles could be performed without significant loss of probe DNA density and activity, demonstrating the potential for reusability, portability and reproducibility of the system.

Cocaine detection using aptamer and molybdenum disulfide-gold nanoparticle-based sensors

Nanomedicine ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 325-335
Author(s):  
Li Gao ◽  
Wenwen Xiang ◽  
Zebin Deng ◽  
Keqing Shi ◽  
Huixing Wang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Molybdenum Disulfide ◽  
Low Cost ◽  
High Sensitivity ◽  
Label Free ◽  
Sensing System ◽  
Plasmon Resonance Band ◽  
Resonance Band ◽  
Cocaine Detection

Aim: The current work highlighted a novel colorimetric sensor based on aptamer and molybdenum disulfide (MoS2)-gold nanoparticles (AuNPs) that was developed for cocaine detection with high sensitivity. Materials & methods: Due to the presence of the plasmon resonance band on the surface of AuNPs, AuNPs aggregated and the color was changed from red to blue after adding a certain concentration of NaCl. We used MoS2 to optimize the sensing system of AuNPs. The folded conformation of the aptamer in combination with cocaine enhanced the salt tolerance of the MoS2-AuNPs, effectively preventing their aggregation. Results & conclusion: The detection limit of cocaine was 7.49 nM with good selectivity. The method based on MoS2-AuNPs colorimetry sensor is simple, quick, label-free and low cost.

scholarly journals An ultra-low noise capacitance to voltage converter for sensor applications in 0.35  µm CMOS

2017 ◽  
Vol 6 (2) ◽  
pp. 285-301 ◽  
Author(s):  
Alexander Utz ◽  
Christian Walk ◽  
Norbert Haas ◽  
Tatjana Fedtschenko ◽  
Alexander Stanitzki ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Signal To Noise Ratio ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Micro Electro Mechanical System ◽  
Low Noise ◽  
Capacitive Pressure Sensor ◽  
Sensor Applications ◽  
Wide Range ◽  
Ultra Low Noise

Abstract. In this paper we present a readout circuit for capacitive micro-electro-mechanical system (MEMS) sensors such as accelerometers, gyroscopes or pressure sensors. A flexible interface allows connection of a wide range of types of sensing elements. The ASIC (application-specific integrated circuit) was designed with a focus on ultra-low noise operation and high analog measurement performance. Theoretical considerations on system noise are presented which lead to design requirements affecting the reachable overall measurement performance. Special emphasis is put on the design of the fully differential operational amplifiers, as these have the dominant influence on the achievable overall performance. The measured input referred noise is below 50 zF/Hz within a bandwidth of 10 Hz to 10 kHz. Four adjustable gain settings allow the adaption to measurement ranges from ±750 fF to ±3 pF. This ensures compatibility with a wide range of sensor applications. The full input signal bandwidth ranges from 0 Hz to more than 50 kHz. A high-precision accelerometer system was built from the described ASIC and a high-sensitivity, low-noise sensor MEMS. The design of the MEMS is outlined and the overall system performance, which yields a combined noise floor of 200 ng/Hz, is demonstrated. Finally, we show an application using the ASIC together with a CMOS integrated capacitive pressure sensor, which yields a measurement signal-to-noise ratio (SNR) of more than 100 dB.

scholarly journals Electrochemical DNA Sensor for Sensitive BRCA1 Detection Based on DNA Tetrahedral-Structured Probe and Poly-Adenine Mediated Gold Nanoparticles

Biosensors ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 78
Author(s):  
Dezhi Feng ◽  
Jing Su ◽  
Guifang He ◽  
Yi Xu ◽  
Chenguang Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gold Nanoparticles ◽  
Early Diagnosis ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Dna Sensor ◽  
Electrochemical Dna Sensor ◽  
Target Dna ◽  
Potential Applications ◽  
Sandwich System

BRCA1 is the biomarker for the early diagnosis of breast cancer. Detection of BRCA1 has great significance for the genetic analysis, early diagnosis and clinical treatment of breast cancer. In this work, we developed a simple electrochemical DNA sensor based on a DNA tetrahedral-structured probe (TSP) and poly-adenine (polyA) mediated gold nanoparticles (AuNPs) for the sensitive detection of BRCA1. A thiol-modified TSP was used as the scaffold on the surface of the screen-printed AuNPs electrode. The capture DNA (TSP) and reporter DNA were hybridized to the target DNA (BRCA1), respectively, to form the typical sandwich system. The nanocomposites of reporter DNA (polyA at the 5′ end) combined with AuNPs were employed for signal amplification which can capture multiple enzymes by the specificity between biotin and streptavidin. Measurements were completed in the electrochemical workstation by cyclic voltammetry and amperometry and we obtained the low limit of detection of 0.1 fM with the linear range from 1 fM to 1 nM. High sensitivity and good specificity of the proposed electrochemical DNA sensor showed potential applications in clinical early diagnosis for breast cancer.

Sign in / Sign up

Export Citation Format

Share Document