The Blue Light Defects Activation in A-Si:H Pin Photodiode as a Biosensor

2020 ◽  
Vol 843 ◽  
pp. 64-69 ◽  
Author(s):  
Vera Gradišnik ◽  
Darko Gumbarević
Keyword(s):  
Energy Distribution ◽  
Blue Light ◽  
Energy Gap ◽  
Point Of Care ◽  
High Sensitivity ◽  
Cmos Technology ◽  
State Density ◽  
Low Noise ◽  
Defect States ◽  
Lab On Chip

The microfluidic Lab-On-Chip (LOC) systems, based on the CMOS technology, today grow rapidly based on requirement of the Point-of-care-testing (POCT). It is a need for a high sensitive biotransducers, as a part of biosensors to be integrated on LOC system. To detect low-level of light emitted by an analyte, promising material and devices are a p-i-n a-Si:H photodiodes. The observed absorbance of blue light in human cells HeLa (cervical carcinoma) induct H2O2 in same cells and consequently, chemical reaction with NO, detected as chemiluminescence signal by the photodiode, as well as formation of cytotoxic singlet oxygen. On the other side a-Si:H p-i-n photodiode has a high sensitivity on blue light at low-light intensity, good spectral responsivity and small reflectance for blue light, low dark current, low-noise in the range of low reverse bias voltages. The photoconductivity of a-Si:H p-i-n photodiode is influenced by the native and light induced localized state density and their energy distribution in the energy gap of intrinsic a-Si:H. It is observed that the defect states of i-layer at various bias voltages contribute to the detection of HeLa cells chemiluminescence. The optical bias dependence of modulated photocurrent method (OBMPC) using the blue LED light is applied to clarify the energy gap density of state nature and energy distribution, respectively in a-Si:H p-i-n photodiode i-layer.

scholarly journals Applications of CMOS Devices for the Diagnosis and Control of Infectious Diseases

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1003
Author(s):  
Saghi Forouhi ◽  
Ebrahim Ghafar-Zadeh
Keyword(s):  
Infectious Diseases ◽  
Influenza A ◽  
Point Of Care ◽  
Low Cost ◽  
Emerging Infectious Diseases ◽  
Cmos Technology ◽  
Disease Diagnosis ◽  
Oxide Semiconductor ◽  
Lab On Chip ◽  
Symptom Screening

Emerging infectious diseases such as coronavirus disease of 2019 (COVID-19), Ebola, influenza A, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) in recent years have threatened the health and security of the global community as one of the greatest factors of mortality in the world. Accurate and immediate diagnosis of infectious agents and symptoms is a key to control the outbreak of these diseases. Rapid advances in complementary metal-oxide-semiconductor (CMOS) technology offers great advantages like high accuracy, high throughput and rapid measurements in biomedical research and disease diagnosis. These features as well as low cost, low power and scalability of CMOS technology can pave the way for the development of powerful devices such as point-of-care (PoC) systems, lab-on-chip (LoC) platforms and symptom screening devices for accurate and timely diagnosis of infectious diseases. This paper is an overview of different CMOS-based devices such as optical, electrochemical, magnetic and mechanical sensors developed by researchers to mitigate the problems associated with these diseases.

scholarly journals Recent Advances of Field-Effect Transistor Technology for Infectious Diseases

Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 103
Author(s):  
Abbas Panahi ◽  
Deniz Sadighbayan ◽  
Saghi Forouhi ◽  
Ebrahim Ghafar-Zadeh
Keyword(s):  
Infectious Diseases ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Limit Of Detection ◽  
Point Of Care ◽  
High Sensitivity ◽  
Cmos Technology ◽  
Oxide Semiconductor ◽  
Label Free ◽  
Effect Transistor

Field-effect transistor (FET) biosensors have been intensively researched toward label-free biomolecule sensing for different disease screening applications. High sensitivity, incredible miniaturization capability, promising extremely low minimum limit of detection (LoD) at the molecular level, integration with complementary metal oxide semiconductor (CMOS) technology and last but not least label-free operation were amongst the predominant motives for highlighting these sensors in the biosensor community. Although there are various diseases targeted by FET sensors for detection, infectious diseases are still the most demanding sector that needs higher precision in detection and integration for the realization of the diagnosis at the point of care (PoC). The COVID-19 pandemic, nevertheless, was an example of the escalated situation in terms of worldwide desperate need for fast, specific and reliable home test PoC devices for the timely screening of huge numbers of people to restrict the disease from further spread. This need spawned a wave of innovative approaches for early detection of COVID-19 antibodies in human swab or blood amongst which the FET biosensing gained much more attention due to their extraordinary LoD down to femtomolar (fM) with the comparatively faster response time. As the FET sensors are promising novel PoC devices with application in early diagnosis of various diseases and especially infectious diseases, in this research, we have reviewed the recent progress on developing FET sensors for infectious diseases diagnosis accompanied with a thorough discussion on the structure of Chem/BioFET sensors and the readout circuitry for output signal processing. This approach would help engineers and biologists to gain enough knowledge to initiate their design for accelerated innovations in response to the need for more efficient management of infectious diseases like COVID-19.

scholarly journals Design and Optimization of a Low Power Pressure Sensor for Wireless Biomedical Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
J. Sosa ◽  
Juan A. Montiel-Nelson ◽  
R. Pulido ◽  
Jose C. Garcia-Montesdeoca
Keyword(s):  
Blood Pressure ◽  
Power Consumption ◽  
Low Power ◽  
Pressure Sensor ◽  
Biomedical Applications ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Cmos Technology ◽  
Low Noise ◽  
Least Significant Bit

A blood pressure sensor suitable for wireless biomedical applications is designed and optimized. State-of-the-art blood pressure sensors based on piezoresistive transducers in a full Wheatstone bridge configuration use low ohmic values because of relatively high sensitivity and low noise approach resulting in high power consumption. In this paper, the piezoresistance values are increased in order to reduce by one order of magnitude the power consumption in comparison with literature approaches. The microelectromechanical system (MEMS) pressure sensor, the mixed signal circuits signal conditioning circuitry, and the successive approximation register (SAR) analog-to-digital converter (ADC) are designed, optimized, and integrated in the same substrate using a commercial 1 μm CMOS technology. As result of the optimization, we obtained a digital sensor with high sensitivity, low noise (0.002 μV/Hz), and low power consumption (358 μW). Finally, the piezoresistance noise does not affect the pressure sensor application since its value is lower than half least significant bit (LSB) of the ADC.

scholarly journals A PVT-Robust Super-Regenerative Receiver with Background Frequency Calibration and Concurrent Quenching Waveform

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1119 ◽  
Author(s):  
Yin ◽  
Fu ◽  
El-Sankary
Keyword(s):  
Data Stream ◽  
Input Data ◽  
Phase Error ◽  
Random Phase ◽  
High Sensitivity ◽  
Cmos Technology ◽  
Low Noise ◽  
Center Frequency ◽  
Noise Performance ◽  
Frequency Calibration

A process-voltage-temperature (PVT)-robust, low power, low noise, and high sensitivity, super-regenerative (SR) receiver is proposed in this paper. To enable high sensitivity and robust-PVT operation, a fast locking phase-locked-loop (PLL) with initial random phase error reduction is proposed to continuously adjust the center frequency deviations of the SR oscillator (SRO) without interrupting the input data stream. Additionally, a concurrent quenching waveform (CQW) technique is devised to improve the SRO sensitivity and its noise performance. The proposed SRO architecture is controlled by two separate biasing branches to extend the sensitivity accumulation (SA) phase and reduce its noise during the SR phase, compared to the conventional optimal quenching waveform (OQW). The proposed SR receiver is implemented at 2.46 GHz center frequency in 180 nm SMIC CMOS technology and achieves better sensitivity, power consumption, noise performance, and PVT immunity compared with existent SR receiver architectures.

scholarly journals Characterization of a dual-beam, dual-camera optical imaging polarimeter

2020 ◽  
Vol 494 (4) ◽  
pp. 4676-4686
Author(s):  
Manisha Shrestha ◽  
Iain A Steele ◽  
Andrzej S Piascik ◽  
Helen Jermak ◽  
Robert J Smith ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Data Reduction ◽  
High Sensitivity ◽  
Cmos Technology ◽  
Low Noise ◽  
Reduction Algorithm ◽  
Dual Beam ◽  
Instrumental Polarization ◽  
Transient Sources

ABSTRACT Polarization plays an important role in various time-domain astrophysics to understand the magnetic fields, geometry, and environments of spatially unresolved variable sources. In this paper we present the results of laboratory and on-sky testing of a novel dual-beam, dual-camera optical imaging polarimeter (MOPTOP) exploiting high sensitivity, low-noise CMOS technology, and designed to monitor variable and transient sources with low systematic errors and high sensitivity. We present a data reduction algorithm that corrects for sensitivity variations between the cameras on a source-by-source basis. Using our data reduction algorithm, we show that our dual-beam, dual-camera technique delivers the benefits of low and stable instrumental polarization (<0.05 per cent for lab data and <0.25 per cent for on sky data) and high throughput while avoiding the additional sky brightness and image overlap problems associated with dual-beam, single-camera polarimeters.

scholarly journals In-Situ Integration of 3D C-MEMS Microelectrodes with Bipolar Exfoliated Graphene for Label-Free Electrochemical Cancer Biomarkers Aptasensor

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 104
Author(s):  
Shahrzad Forouzanfar ◽  
Nezih Pala ◽  
Chunlei Wang
Keyword(s):  
High Performance ◽  
Microelectromechanical Systems ◽  
Point Of Care ◽  
High Sensitivity ◽  
Label Free ◽  
Lab On Chip ◽  
Electrochemical Label ◽  
Mems Technology ◽  
On Chip

The electrochemical label-free aptamer-based biosensors (also known as aptasensors) are highly suitable for point-of-care applications. The well-established C-MEMS (carbon microelectromechanical systems) platforms have distinguishing features which are highly suitable for biosensing applications such as low background noise, high capacitance, high stability when exposed to different physical/chemical treatments, biocompatibility, and good electrical conductivity. This study investigates the integration of bipolar exfoliated (BPE) reduced graphene oxide (rGO) with 3D C-MEMS microelectrodes for developing PDGF-BB (platelet-derived growth factor-BB) label-free aptasensors. A simple setup has been used for exfoliation, reduction, and deposition of rGO on the 3D C-MEMS microelectrodes based on the principle of bipolar electrochemistry of graphite in deionized water. The electrochemical bipolar exfoliation of rGO resolves the drawbacks of commonly applied methods for synthesis and deposition of rGO, such as requiring complicated and costly processes, excessive use of harsh chemicals, and complex subsequent deposition procedures. The PDGF-BB affinity aptamers were covalently immobilized by binding amino-tag terminated aptamers and rGO surfaces. The turn-off sensing strategy was implemented by measuring the areal capacitance from CV plots. The aptasensor showed a wide linear range of 1 pM–10 nM, high sensitivity of 3.09 mF cm−2 Logc−1 (unit of c, pM), and a low detection limit of 0.75 pM. This study demonstrated the successful and novel in-situ deposition of BPE-rGO on 3D C-MEMS microelectrodes. Considering the BPE technique’s simplicity and efficiency, along with the high potential of C-MEMS technology, this novel procedure is highly promising for developing high-performance graphene-based viable lab-on-chip and point-of-care cancer diagnosis technologies.

Novel High Sensitivity Tuberculosis Point-of-Care Test for People Living with HIV

2018 ◽  
Author(s):  
Tobias Broger ◽  
Bianca Sossen ◽  
Elloise du Toit ◽  
Andrew D. Kerkhoff ◽  
Charlotte Schutz ◽  
...  
Keyword(s):  
Point Of Care ◽  
High Sensitivity ◽  
People Living With Hiv ◽  
Point Of Care Test ◽  
Living With Hiv

Trends in Diagnosis for Active Tuberculosis Using Nanomaterials

2019 ◽  
Vol 26 (11) ◽  
pp. 1946-1959 ◽  
Author(s):  
Le Minh Tu Phan ◽  
Lemma Teshome Tufa ◽  
Hwa-Jung Kim ◽  
Jaebeom Lee ◽  
Tae Jung Park
Keyword(s):  
Sensitivity And Specificity ◽  
High Efficiency ◽  
Point Of Care ◽  
High Sensitivity ◽  
Signs And Symptoms ◽  
Diagnostic Methods ◽  
Advantages And Disadvantages ◽  
Treatment And Prevention ◽  
Clinical Tools ◽  
Diagnostic Applications

Background:Tuberculosis (TB), one of the leading causes of death worldwide, is difficult to diagnose based only on signs and symptoms. Methods for TB detection are continuously being researched to design novel effective clinical tools for the diagnosis of TB.Objective:This article reviews the methods to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods based on nanomaterials.Methods:The current methods for TB diagnosis were reviewed by evaluating their advantages and disadvantages. Furthermore, the trends in TB detection using nanomaterials were discussed regarding their performance capacity for clinical diagnostic applications.Results:Current methods such as microscopy, culture, and tuberculin skin test are still being employed to diagnose TB, however, a highly sensitive point of care tool without false results is still needed. The utilization of nanomaterials to detect the specific TB biomarkers with high sensitivity and specificity can provide a possible strategy to rapidly diagnose TB. Although it is challenging for nanodiagnostic platforms to be assessed in clinical trials, active TB diagnosis using nanomaterials is highly expected to achieve clinical significance for regular application. In addition, aspects and future directions in developing the high-efficiency tools to diagnose active TB using advanced nanomaterials are expounded.Conclusion:This review suggests that nanomaterials have high potential as rapid, costeffective tools to enhance the diagnostic sensitivity and specificity for the accurate diagnosis, treatment, and prevention of TB. Hence, portable nanobiosensors can be alternative effective tests to be exploited globally after clinical trial execution.

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