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Detection of Creatinine Using Molecularly Imprinted Polymers (MIP) Technique
(2022-01-01)
Pitayataratorn, Teerachote
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Sukjee, Wannisa
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Sangma, Chak
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Visitsattapongse, Sarinporn
An electrochemical potentiometric biosensor based on the molecularly imprinted polymer (MIP) technique has been fabricated for creatinine detection. The polymer consists of azobisisobutyronitrile (AIBN) as an initiator together with N, N'(1,2-Dihydroxyethelene) bisacrylamide (DHEBA) as a cross-linker and graphene oxide (GO) was prepared along with several functional monomers combination to compare each combination's effectiveness in the detection of creatinine. An experiment was divided into imprint and non-imprint polymer for imprinting effectiveness evaluation. Creatinine anhydrous were used as template molecules for imprinting the polymer. The analyte was prepared in buffer solution (PBS) at a pH of 7.4 with a concentration range from 0.01 mg/dl to 100 mg/dl. N-hydroxy succinimide (NHS) and D-glucose were used for the specificity test. This study can conclude that polymers consisting of functional monomer methyl methacrylate (MMA) and acrylamide (AAM) with a 1:1 ratio show significant sensitivity to creatinine with the detection limit of 0.1 mg/dl along with remarkable selectivity to creatinine against other negative control compared to other conditions in this study and the sensor has a response linearly ranges from 0.01 to 100 mg/dl.
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Study of ni2+/ni3+ redox couple and electrocatalytic responses of ni on nitrogen-doped carbon for urea non-enzymatic detection
(2021-01-01)
Asavakijthananont, Narawee
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Janyasupab, Metini
A novel redox couple of metallic nickel (Ni) catalyst can become a great candidate of non-enzymatic detection. By taking advantage of fast electron transfer, Ni redox couples can be tailored as pseudo-enzyme in urea measurement. In this study, Ni catalyst on nitrogen doped carbon (Ni-NC) was synthesized and characterized morphological, elemental, and electrocatalytic properties in comparison to different configuration of pure nickel (Ni), Ni with carbon (Ni-C), and bare carbon electrode, assessed by cyclic voltammetry and differential pulse voltammetry. By examining various Ni redox couples in rapid electron transfer process, the prominent anodic and cathodic peaks of Ni2+/Ni3+ were applicable to detect urea in the detection range of 1-20 mM, with an excellent sensitivity and relative standard deviation of 1.634 µA.mM-1 (R2 of 0.989) and 4.89%, respectively. Therefore, Ni-NC can find practical applications for material sensing device toward non-enzymatic urea measurement.
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Low-voltage low-pass and band-pass elliptic filters based on log-domain approach suitable for biosensors
(2019-12-02)
Prommee, Pipat
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Wongprommoon, Natapong
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Kumngern, Montree
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Jaikla, Winai
This research proposes bipolar junction transistor (BJT)-based log-domain high-order elliptic ladder low-pass (LPF) and band-pass filters (BPF) using a lossless differentiator and lossless and lossy integrators. The log-domain lossless differentiator was realized by using seven BJTs and one grounded capacitor, the lossy integrator using five BJTs and one grounded capacitor, and the lossless integrator using seven BJTs and one grounded capacitor. The simplified signal flow graph (SFG) of the elliptic ladder LPF consisted of two lossy integrators, one lossless integrator, and one lossless differentiator, while that of the elliptic ladder BPF contained two lossy integrators, five lossless integrators, and one lossless differentiator. Log-domain cells were directly incorporated into the simplified SFGs. Simulations were carried out using PSpice with transistor array HFA3127. The proposed filters are operable in a low-voltage environment and are suitable for mobile equipment and further integration. The log-domain principle enables the frequency responses of the filters to be electronically tunable between 10k Hz–10 MHz. The proposed filters are applicable for low-frequency biosensors by reconfiguring certain capacitors. The filters can efficiently remove low-frequency noise and random noise in the electrocardiogram (ECG) signal.
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Development of wireless based potentiostat in biomedical applications
(2019-03-01)
Janyasupab, Metini
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Asavakijthananont, Narawee
Wirelessly integrated and portable electronics designs of analytical systems are of great importance to support future technological platforms including internet of things (IoT), artificial intelligence (AI), precision medicine, and wearable chemical/biological sensing systems. In this study, a simple and robust prototype of the so-called potentiostat, electrochemical instrumental system, with a wireless data acquisition and user control is demonstrated. With a wide range of potential applications, the developed system can be conveniently customizable to detect chemical of interest in food safety, continuous at-home diagnosis, environmental monitoring, and low-power energy storage. The device is comprised of two major units: a modified front-end sensor (Texas Instrument, LMP91000EVM), and a development board (Espressif, ESP32) implementing with a programmable saw tooth waveform to assess cyclic voltammetry (CV), the most common electrochemical measurement with the three-electrode configuration, namely working electrode, reference electrode and auxiliary electrode. In particular, the prototype shows a good agreement of CV in a standard electron transfer experiment by monitoring the interchange state of Fe2+ and Fe3+ ion in ferricyanide solution with potassium chloride supported, in comparison to that of the commercial potentiostat. Furthermore, the effects of different scan rate (0.05 to 0.15 V/s) and different ferricyanide concentrations from 1 to 7.5 millimolar are also evaluated to quantify sensing performance. Based on the obtained results, the calibration curve of anodic peak and cathodic peak current are linearly correlated with R2 of 0.9987 and 0.9990, respectively, providing a cost-effective (less than USD 80) and portable solution to the future integration of sensing technology.
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ISFET's Interface Circuit for Biomedical Applications Using Delta-Sigma Modulation
(2019-01-10)
Bumrungyat, Puvanat
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Kasemsuwan, Varakorn
This paper presents a new ISFET's interface circuit for biomedical applications using delta-sigma modulation. The proposed design operates ISFET in the linear region so that an output current is linearly dependent on pH over a wide range (pH 2 to pH 14). Conversion to a digital output domain is done using a sigma-delta converter making the interface circuit very robust and reliable for most sensor applications. The proposed circuit is designed in a 0.18 μm technology. The supply voltage is 1.8 V and the total current drawn is 56 μA. The simulation results show that the proposed circuit can sense a pH with an error within the range of -0.2% to 0.3% for pH ranging from 2 to 14.
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Electrocatalytic study of low-cost bimetallic cobalt/iron catalyst on carbon for non-enzymatic glucose sensor in human urine
(2019-01-01)
Janyasupab, Metini
;
Liu, Chen Wei
This study investigated an electrocatalytic behavior of non-enzymatic glucose detection in urine by using low-cost non-precious metal CoFe catalyst on carbon (C) supported. The bimetal catalyst was prepared by the reduction of oleic acid and loaded 10% wt. metal onto the activated carbon. Due to the synergistic effect, CoFe exhibited its intrinsic electrocatalytic property, suitable for the chemisorption of glucose molecule and the d-electron of metal. For morphology and elemental composition, CoFe/C was characterized by Transmission Electron Microscopy (TEM), and X-ray Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD), exhibiting Co(111) and Fe2O3(104) with the nanocluster average diameter of 25 nm. More importantly, electrocatalytic behaviors of CoFe/C were assessed by cyclic voltammetry (CV) and Differential Pulse Voltammetry (DPV) on the glassy carbon rotating disk electrode for glucose detection (0-3 mM) in modified artificial urine (mAUM), and human urine specimens. In particular, excellent sensitivities from the lower range of glucose level (< 1 mM) and the higher level by DPV in mAUM were estimated to be 318.42 and 82.20 µA.cm-2.mM-1 with the correlation coefficient (R2 ) values of 0.90 and 0.94, respectively. Furthermore, the as-prepared CoFe/C biosensor also demonstrated practical measurement in human urine sample with the sensitivity of 59.72 µA.cm-2.mM-1 (R2 = 0.99) without any electron facilitators (e.g. sodium hydroxide), thereby providing a promising cost-effective catalyst design for future technology of non-enzymatic glucose sensing applications in urine.
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Modeling and analysis of a microresonating biosensor for detection of salmonella bacteria in human blood
(2014-07-18)
Bahadoran, Mahdi
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Noorden, Ahmad Fakhrurrazi Ahmad
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Chaudhary, Kashif
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Mohajer, Faeze Sadat
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Aziz, Muhammad Safwan
A new photonics biosensor configuration comprising a Double-side Ring Add-drop Filter microring resonator (DR-ADF) made from SiO2-TiO2 material is proposed for the detection of Salmonella bacteria (SB) in blood. The scattering matrix method using inductive calculation is used to determine the output signal's intensities in the blood with and without presence of Salmonella. The change in refractive index due to the reaction of Salmonella bacteria with its applied antibody on the flagellin layer loaded on the sensing and detecting microresonator causes the increase in through and dropper port's intensities of the output signal which leads to the detection of SB in blood. A shift in the output signal wavelength is observed with resolution of 0.01 nm. The change in intensity and shift in wavelength is analyzed with respect to the change in the refractive index which contributes toward achieving an ultra-high sensitivity of 95,500 nm/RIU which is almost two orders higher than that of reported from single ring sensors and the limit of detection is in the order of 1 × 10-8 RIU. In applications, such a system can be employed for a high sensitive and fast detection of bacteria. © 2014 by the authors; licensee MDPI, Basel, Switzerland.
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Real-time monitoring glucose by used microwave antenna apply to biosensor
(2011-12-01)
Wiwatwithaya, Sujitra
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Phasukkit, Pattarapong
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Tungjitkusolmun, Supan
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Wongtrairat, Wannaree
In this paper we investigate the electromagnetic field interaction with a glucose aqueous solution using a microwave antenna (U-shape) to evaluate the glucose concentration and vary temperature. The glucose concentration vary from 10-40 mg/ml compare with DI(de-ionized) water, the operating frequency of about 1-2.5GHz. The change of the glucose concentration is directly related to the change of the reflection coefficient due to electromagnetic interaction between the dielectric wave and the glucose aqueous solution. A glucose biosensor using microwave antenna (U-shape) provides a unique approach for glucose monitoring. The antenna is designed have various formed and test by comsol program. The principles of Comsol is finite element for dispersion of electromagnetic waves from a real experiment to measure the concentration of glucose solution. © 2011 IEEE.

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