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Keloid scarring is an abnormal scar disease characterised by excessive proliferation of fibroblasts and over-deposition of collagen during wound healing. Although various treatments for keloid scars have been developed, preventive medicine is believed to be a promising strategy. The skin barrier limits the gentle topical administration of medicaments such as creams and hydrogel dressings, resulting in reduced therapeutic efficacy. In recent years, microneedles (MNs) have been regarded as an appreciable device for topical administration without inducing side effects, and they are painless and do not cause bleeding. In this study, an MN patch with controlled transdermal dual-drug release was developed to achieve combinatory treatment of keloid scars using a heterogeneous gelatin-structured composite MN. Gelatin hydrogel was used as a substrate to load gallic acid (GA) and quercetin-loaded amphiphilic gelatin nanoparticles to fabricate dual-drug heterogeneous composite MNs. The results of the insertion test and mechanical properties of the MNs showed that the heterogeneous composite MN patches could be self-pressed into the stratum corneum and control dual-drug release at different time periods. GA was released at an earlier stage to retard the proliferation of fibroblasts, and quercetin was released at a later stage as a strong antioxidant to erase the generation of reactive oxygen species. Furthermore, real-time quantitative polymerase chain reaction data indicated that the gene expression of fibroblasts (such as Col I and III) was downregulated in the dual-drug system. The above results demonstrate that using heterogeneous composite MNs with the combination of dual-drug pharmacology is beneficial for preventing keloid scar formation.

Osteoarthritis (OA) is a globally occurring articular cartilage degeneration disease that adversely affects both the physical and mental well-being of the patient, including limited mobility. One major pathological characteristic of OA is primarily related to articular cartilage defects resulting from abrasion and catabolic and proinflammatory mediators in OA joints. Although cell therapy has hitherto been regarded as a promising treatment for OA, the therapeutic effects did not meet expectations due to the outflow of implanted cells. Here, we aimed to explore the repair effect of magnetized chondrocytes using magnetic amphiphilic-gelatin nanocarrier (MAGNC) to enhance cellular anchored efficiency and cellular magnetic guidance (MG) toward the superficial zone of damaged cartilage. The results of in vitro experiments showed that magnetized chondrocytes could be rapidly guided along the magnetic force line to form cellular amassment. Furthermore, the Arg-Gly-Asp (RGD) motif of gelatin in MAGNC could integrate the interaction among cells to form cellular stacking. In addition, MAGNCs upregulated the gene expression of collagen II (Col II), aggrecan, and downregulated that of collagen I (Col I) to reduce cell dedifferentiation. In animal models, the magnetized chondrocytes can be guided into the superficial zone with the interaction between the internal magnetic field and MAGNC to form cellular stacking. In vivo results showed that the intensity of N-sulfated-glycosaminoglycans (sGAG) and Col II in the group of magnetized cells with magnetic guiding was higher than that in the other groups. Furthermore, smooth closure of OA cartilage defects was observed in the superficial zone after 8 weeks of implantation. The study revealed the significant potential of MAGNC in promoting the high-density stacking of chondrocytes into the cartilage surface and retaining the biological functions of implanted chondrocytes for OA cartilage repair.

Glycated albumin(GA), a biomarker which has great potential to replace glycated hemoglobin in the diagnosis and treatment of diabetes, is being extensively studied by scientists, especially in preventive medicine. Aptamers, as novel probes, have attracted much attention due to their high specificity, wide storage conditions, and simple preparation. However, the interaction mechanism between GA and its aptamer is still unclear, hindering the progress of diabetic aptamer sensors into clinical testing. In this study, the interaction mechanism between GA and its aptamer was evaluated for the first time using surface plasmon resonance by changing the pH value, salt concentration and temperature. The successful preparation of the sensor chip is proved by the water contact angle, Atomic Force Microscope, and the X-ray photoelectron spectroscopy. This study shows that the pH can greatly affect the formation of a complex from the interaction between the aptamer and GA. The interaction mechanism between GA aptamer and GA was caused by electrostatic force. Otherwise, this is the first time to detect protein isoelectric point (pI) using SPR. This study provides an important reference for researchers of aptamer sensors from the perspective of detection environment, and promotes the use of aptamer sensors to the clinic.

Diabetes mellitus is one of the most common noncommunicable diseases in the world. Fasting blood glucose level is one of the diabetes diagnostic criteria, but it is readily affected by stress, exercise and many other factors. Glycated hemoglobin (HbA1c) is an important clinical index for diabetes and related diseases. In this study, a cheaper, rapid-prototyping, high-sensitivity angle-scanning surface plasmon resonance (SPR) was developed by fused deposition modeling (FDM) 3D printing technology for HbA1c detection. The sensor chip is based on an aptamer that has high affinity and high specificity to HbA1c. The results showed that this HbA1c-specific aptamer had high specificity for HbA1c, and the calculated KD was 6.13 × 10−8 M. The linear detection response of HbA1c appeared in the range of 18–147 nM, with a detection limit of 1 nM. This SPR HbA1c detection system could be a promising platform for developing clinical point-of-care diagnostic applications.

Blood glucose monitoring is a valuable tool for managing diabetes. In recent years, with the increase of diabetics in the world, continuous monitoring of blood sugar changes has attracted more and more researchers’ attention. Among the current technologies for measuring glucose, optical and electrochemical glucose sensors are the mainstream ones. This article introduces the history of optical, electrochemical, and other sensors such as field effect transistors sensors and their advantages and disadvantages respectively. This review summarizes the research progress and main challenges of continuous glucose monitoring technology. We found that different optical techniques have different limitations which restricts the development of optical CGM. In contrast, electrochemical glucose sensors are more feasible and reliable in implementing CGM. Therefore, this review focuses on the development and shortcomings of electrochemical sensors, especially the promising DET and the current commercial CGM. Hopefully, it will help readers sort out the future of CGM’s development.

In recent years, with the rise of global diabetes, a growing number of subjects are suffering from pain and infections caused by the invasive nature of mainstream commercial glucose meters. Non-invasive blood glucose monitoring technology has become an international research topic and a new method which could bring relief to a vast number of patients. This paper reviews the research progress and major challenges of non-invasive blood glucose detection technology in recent years, and divides it into three categories: optics, microwave and electrochemistry, based on the detection principle. The technology covers medical, materials, optics, electromagnetic wave, chemistry, biology, computational science and other related fields. The advantages and limitations of non-invasive and invasive technologies as well as electrochemistry and optics in non-invasives are compared horizontally in this paper. In addition, the current research achievements and limitations of non-invasive electrochemical glucose sensing systems in continuous monitoring, point-of-care and clinical settings are highlighted, so as to discuss the development tendency in future research. With the rapid development of wearable technology and transdermal biosensors, non-invasive blood glucose monitoring will become more efficient, affordable, robust, and more competitive on the market.

Glycated hemoglobin (HbA1c) has been widely explored as an important marker for monitoring and diagnosing diabetes. Due to the advantages of high selectivity, easy preparation, and convenient preservation of aptamers, research on glycated hemoglobin detection utilizing aptasensors has received much attention in recent years. However, factors such as the pH and the salt concentration of the solution and the structure of the aptamer could influence the interactions between HbA1c and the aptamer. In this study, the factors were evaluated using surface plasmon resonance (SPR). The results show that the pH and the salt concentration can greatly affect the formation of a complex between the aptamer and HbA1c. In the stereostructure of the aptamer, loop L1 may be an important motif for recognizing glycated hemoglobin. In addition, the best condition for detecting HbA1c was at pH 6, with a high sensitivity and a low limit of detection(LOD) (1.06 × 10−3 RU nM /2.55 nM). The results also demonstrated that the use of an SPR aptamer biosensor can be a sensitive technique to improve the accuracy and correctness of HbA1c measurement.

Polydimethylsiloxane (PDMS) is often used in flexible electronic skin, due to their non toxic and tough. However, the lack of degradation and cell biocompatibility of PDMS would limit the potential use in the biological field. To overcome the limitation, PDMS was modified by surface treatment for enhancing cell adhesion and proliferation. This research is focused on preparation and evaluation of novel chitosan biocompatible electronic skin. Chitosan electronic skin was prepared by a thermal induced phase separation method, following treatment with NaOH gelating agent, followed by analyzing the surface morphology, swelling behavior, mechanical strength, degradation rate. The electrode was produced by screen printing technique, followed by analyzing the adhesion between the ink and cell biocompatibility. From scanning electron microscope (SEM) observations, NaOH gelated chitosan skin had the smooth surface morphology. The swelling ratio of all chitosan skin gelated by NaOH were less than 5%. The chitosan skin, prepared by 300k kDa chitosan gelated by NaOH for 3hr, had the smallest swelling ratio. Furthermore, its mechanical strength showed the highest value of Young’s modulus (∼151 kPa). It indicated that 300 kD chitosan skin gelated by NaOH for 3hr had better size stability. All chitosan skins degraded about 20% of initial weight after 40 days in vitro shaking test. The adhesion strength of the silver inks on the surface of chitosan was better than carbon ink, and the electrical characteristic is almost the same with commercial polycarbonate (PC) substrate. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and SEM observation indicated that chitosan skin with silver electrode showed the cell biocompatibility. By further increasing the application of both screen imprinting technique and biopolymer, the idea of interdisciplinary can be achieved and it would be a creative revolution to the field of wearable device into tissue engineering.

Hydrothermal carbon (HTC) is typically well-dispersed, but it remains a great challenge for HTC to become conductive. Co-doping with heteroatoms has been confirmed to be an effective strategy to significantly promote the electrical conductivity of carbon. Moreover, there is no simple and green method to construct sensitive HTC based electrochemical biosensors until now. In this paper, N and S dual-doped carbon (NS-C) with ultra-low charge transfer resistance is easily synthesized from L-cysteine and glucose in a hydrothermal reaction system. The morphology, structural properties and electrochemical properties of the as-prepared NS-C are analyzed. In comparison with the undoped hydrothermal (UC) modified glassy carbon electrode (GCE), the charge transfer resistance of UC (476 Ω) is ten times the value of NS-C (46 Ω) . The developed biosensor shows a better performance to detect glucose in a wide concentration range (50–2500 μmol L−1) with the detection limit of 1.77 μmol L−1 (S/N=3) and a high sensitivity (0.0554 μA cm−2 μmol−1 L). The apparent Michaelis-Menten constant value of GCE/NS-C/GOx/nafion modified electrode is 0.769 mmol L−1, indicating a high affinity of glucose oxidase to glucose. These results demonstrate that the hydrothermal method is an effective way for preparing high electrical conductivity carbon with excellent performances in biosensor application.

In this study, we developed a screen-printed carbon−graphene-based electrochemical biosensor for EN2 protein detection. The engrailed-2 (EN2) protein, a biomarker for prostate cancer, is known to be a strong binder to a specific DNA sequence (5′-TAATTA-3′) to regulate transcription. To take advantage of this intrinsic property, aptamer probes with TAATTA sequence was immobilized onto the screen-printed carbon−graphene electrode surface via EDC−NHS coupling approach. Cyclic voltammetry (CV) of the electrochemical measurement technique was employed for the quantitative detection of EN2 protein. The hindrance to the redox reaction of potassium ferricyanide on the biosensor surface due to the binding of the immobilized aptamer with its target EN2 protein quantified the protein concentration. Under optimum conditions, the aptamer biosensor can detect EN2 protein over a linear range from 35 to 185 nM with a detection limit of 38.5 nM.

A whole paper electro-biosensor detection platform for detecting glucose is reported. Glucose oxidase was immobilized on paper-based screen-printed carbon electrodes. The developed biosensor has an excellent electrochemical characteristic and high heterogeneous electron transfer rate constant (ks = 4.23 × 10−4). This new detection platform exhibited good amperometric responses toward glucose, with a wide linear range up to 10 mM with R2 is 0.9973 and the sensitivity is 2.07 μA mM−1. The parallel measurements of glucose by different biosensors had a low relative standard deviation of 4.26 % and demonstrated it had good reproducibility. In the interference studies, there was no significant difference with ascorbic acid or uric acid. For stability, it retained 93.9 % of its initial response after a storage period of 31 days in 4 °C. Besides, the Parkes error grid analysis was indicated that paper-based electrochemical biosensor has a good accuracy on the glucose detection.

Porous silicon nanodisks (PSD) were fabricated by the combination of photolithography and electrochemical etching of silicon. By using PSD as a reducing agent, gold nanorods (AuNR) were in situ synthesized in the nanopores of PSD, forming PSD-supported-AuNR (PSD/AuNR) hybrid particles. The formation mechanism of AuNR in porous silicon (pSi) was revealed by exploring the role of pSi reducibility and each chemical in the reaction. With the PSD support, AuNR exhibited a stable morphology without toxic surface ligands (CTAB). The PSD/AuNR hybrid particles showed enhanced plasmonic property compared to free AuNR. Because high-density "hot spots" can be generated by controlling the distribution of AuNR supported in PSD, surface-enhanced raman scattering (SERS) using PSD/AuNR as particle substrates was demonstrated. A multifunctional vector, PSD/AuNR/DOX, composed of doxorubicin (DOX)-loaded PSD/AuNR capped with agarose (agar), was developed for highly efficient, combinatorial cancer treatment. Their therapeutic efficacy was examined using two pancreatic cancer cell lines, PANC-1 and MIA PaCa-2. PSD/AuNR/DOX (20 μg Au and 1.25 μg DOX/mL) effectively destroyed these cells under near-IR laser irradiation (810 nm, 15 J·cm(-2) power, 90 s). Overall, we envision that PSD/AuNR may be a promising injectable, multifunctional nanovector for biomedical application.

Detection of pathogenic bacteria in dairy farms and processing plants is important for milk quality control. In this study, a simple in situ method for determining the bacterial concentration in milk was developed with an interdigitated microelectrode sensor. This method was based on a punctual measurement of the electrode–milk interface impedance change due to bacterial metabolism in the milk. The interface impedance varied predominately at low frequencies, attributed to the change on the double-layer capacitance. The detection time TD, defined as the time required to attain a −10% impedance change at 10 Hz, became a practicable means for the estimation of initial E. coli concentration in milk samples. Regression analysis resulted in a third-order polynomial relationship between the detection time and the logarithm of the initial E. coli concentration (N0, cells/ml) in a milk sample, i.e., log N0 = 11.48 – 2.33 TD + 0.288(TD)2 – 0.0154(TD)3 with R2 = 0.9988. The sensor was able to detect E. coli in milk of initial concentrations as low as 7 cells/ml. The proposed impedance sensor is suitable for determining bacterial contamination at dairy farms and processing plants.

As the number of diabetic patients increases year by year, the demand for a self-monitoring blood glucose test also increases. Additionally, more in-depth studies of blood glucose biosensors have led to increasing accuracy requirements. However, at present, most enzyme glucose sensors have difficulty solving issues related to hematocrit (HCT) interference. Most studies on anti-HCT interference in blood glucose sensing have mainly focused on correction factors, such as glucose correction, and electrical impedance or resistivity characteristics to correct the impact of HCT. In this work, we developed an anti-HCT-interference blood glucose sensor based on a fiber paper-based screen-printed carbon electrode with a mediator (potassium ferricyanide) and glucose oxidase (GOD), which were fixed through inkjet printing. When testing whole blood samples with HCT levels of 20%–70% and a fluid dropping method, the results of a consensus error grid analysis showed that 91% of the data points lied within zones A and B. The glucose sensor was exclusively designed with a 16 μL chamber in the working area of the sensor. When the testing fluid was taken in by capillary sucking, the effect of HCT was further reduced, and 95% of the data points lied within zones A and B in the consensus error grid.

Skin penetration is related to efficiencies of drug delivery or ISF extraction. Normally, the macro-electrode is employed in skin permeability promotion and evaluation, which has the disadvantages of easily causing skin damage when using electroporation or reverse iontophoresis by alone; furthermore, it has large measurement error, low sensitivity, and difficulty in integration. To resolve these issues, this paper presents a flexible interdigital microelectrode for evaluating skin penetration by sensing impedance and a method of synergistical combination of electroporation and reverse iontophoresis to promote skin penetration. First, a flexible interdigital microelectrode was designed with a minimal configuration circuit of electroporation and reverse iontophoresis for future wearable application. Due to the variation of the skin impedance correlated with many factors, relative changes of it were recorded at the end of supply, different voltage, or constant current, times, and duration. It is found that the better results can be obtained by using electroporation for 5 min then reverse iontophoresis for 12 min. By synergistically using electroporation and reverse iontophoresis, the penetration of skin is promoted. The results tested in vivo suggest that the developed microelectrode can be applied to evaluate and promote the skin penetration and the designed method promises to leave the skin without damage. The electrode and the method may be beneficial for designing noninvasive glucose sensors.

Surface plasmon resonance (SPR) is a real-time, label-free, and high-sensitive detection technology. SPR has been widely used in many applications such as biomolecular interaction analysis, environmental monitoring, and medical diagnostics. However, conventional SPR sensor systems usually require expensive equipment and complicated optics. In this paper, we have demonstrated a rapid prototyping of angle-scanning SPR for bioanalytical investigation. Rapid prototyping was attained by utilizing the FDM (fused deposition modeling) based 3D (three-dimensional) printing technology. Two rotating platforms were employed to drive the laser source and photodiode, respectively. A temperature regulation unit was incorporated to maintain the system temperature in order to reduce the temperature effect. The proposed SPR rapid prototyping yielded a refractive index resolution of 6.4×10−6 RIU (refractive index unit), and the biotin-avidin system validated the kinetics parameters measurement capability. The obtained results indicated that the FDM 3D printing has great potential for developing rapid-prototyping SPR system.

In this study, we developed an interdigitated gold microelectrode-based impedance sensor to detect Escherichia coli (E. coli) in human urine samples for urinary tract infection (UTI) diagnosis. E. coli growth in human urine samples was successfully monitored during a 12-h culture, and the results showed that the maximum relative changes could be measured at 10Hz. An equivalent electrical circuit model was used for evaluating the variations in impedance characteristics of bacterial growth. The equivalent circuit analysis indicated that the change in impedance values at low frequencies was caused by double layer capacitance due to bacterial attachment and formation of biofilm on electrode surface in urine. A linear relationship between the impedance change and initial E. coli concentration was obtained with the coefficient of determination R(2)>0.90 at various growth times of 1, 3, 5, 7, 9 and 12h in urine. Thus our sensor is capable of detecting a wide range of E. coli concentration, 7×10(0) to 7×10(8) cells/ml, in urine samples with high sensitivity.

The piezoelectric biosensor have been widely used in ultra-small mass detection of biomolecular, based on PZT piezoelectric material can create a variety of compositions geometrically; it could widely develop a high-frequency resonator and measure the change of the slightest mass while improve the limited detection simultaneously. Therefore, the piezoelectric biosensor of this study was fabricated by a spin-coating method and backside etching process for improving the characteristic of piezoelectric biosensor. The result exhibited that the 250 μm × 250 μm working size has the most favorable piezoelectric characteristic. The tunability was approximately 38.56 % and it showed that reducing the substrate thickness could obtain a clear resonance signal in a range of 60 to 380 MHz. In theory calculated for gravimetric sensing, it could achieve 0.1 ng sensing sensitivity. In gravimetric sensing, the sensing range was between 50,000~100,000 CFU/ml. Sensing range was lower in clinical urinary tract infection (100,000 CFU/ml), thus demonstrating its usefulness for preventive medicine. It can understand the piezoelectric sensor of this study has potential application in the future for biomedical gravimetric sensing.

A portable impedance measurement system was used to monitor the growth of L929 cells. The interdigitating microelectrodes of our portable system were produced by microfabrication technology with a width of 8 μm, a gap of 8 μm, and a length of 500 μm. These microelectrodes provided a high electric field for AC impedance measurements. When mouse L929 cells were cultured on the electrode surface and pre-coated with poly- l -lysine, the changes in the impedance on the interdigitating electrodes represented the lag, log, and stationary phases of a typical cell growth curve. The impedance measurement result was fitted to an equivalent circuit, which showed that the capacitance signal was the major contributor to the total impedance of the cell culture. The capacitance arises from the cell capacitance, the double-layer capacitance and the capacitance of the poly- l -lysine-coated surface, and the changes in capacitance were probably due to cell proliferation and the resulting changes in cell metabolites. To make the device portable and provide rapid results, we designed a novel impedance detection system comprised of a microprocessor, an AD5933 impedance converter (IC), and the interdigitating microelectrodes. This device was successfully used to observe the changes in the metabolism and proliferation of L929 cells at different stages of cell growth with low cell concentrations. Further, the portable impedance measurement device is a useful analytical tool for monitoring cell growth. It will integrate easily with wireless circuits for applications in aseptic cell biology.

Human serum albumin (HSA) is an important biomarker for diagnosing nephropathy. Traditional microalbumin detection is easy affected by the intake of certain medicines, such as aspirin, corticosteroids and antibiotics. In this research, the surface plasmon resonance (SPR) biosensor technique was used to detect HSA. The anthraquinone dye Cibacron Blue F3G-A (CB) is used as a receptor which has a specific affinity for HSA. The purpose of this study is establishing the optimum conditions for SPR to detect HSA. The results exhibited that the sensor chip has high affinity as well as high capacity at pH 4 with 0.05 M sodium chloride. In addition, linear response appeared in the range of 0.01–0.1 mg/ml HSA and the detecting limit was 4 μg/ml. This methodology may prove to be useful in clinical diagnosis and may serve as an assay for HSA binding ability.

Piezoelectric sensors made of quartz, Pb(Zr,Ti)O 3 , Pb(La,Zr,Ti)O 3 , or Pb(Zr,Ti,Sn)O y have rapidly been developed recently because of the potential applications in devices such as biosensors, accelerometers, pressure sensors, and ultrasonic transducers. However, the development of devices with reduced size but with improved sensitivity is highly important. With this idea, the study aims to develop a lead zironate titanate (PZT) chip as a novel gravimetric biosensor using the resonance feature in biomolecule detection. The PZT thin film characterized by the X-ray diffractometer (XRD) has a perovskite structure. The fabricated PZT sensor was designed with 250 μm × 250 μm-sensing areas of electrodes, determined by the measured impedance at 98.5 MHz frequency. The morphology and cross-section of scanning electron microscope (SEM) images show that the thickness of the spin-on PZT layer was about 500 nm and the crystal grain size was less than 50 nm. Moreover, an evaluation circuit consisted of a resonance circuit and a frequency-to-voltage circuit was established to detect bovine serum albumin (BSA) protein. The PZT sensor, combined with evaluation circuit, showed a high sensitivity of 62.8 Hz cm 2 /ng. The detection sensitivity was enhanced by 300 folds than that of traditional quartz crystal microbalance (QCM).

Glycated hemoglobin (HbA1c) is formed by a nonenzymatic reaction of glucose with the N-terminal valine of adult hemoglobin's beta-chain. The amount of HbA1c reflects the average concentration of glucose variation level over the preceding 2 to 3 months. Because the boronate has antibody mimicking for HbA1c, often it is used to detect HbA1c. However, factors such as the ratio of the phenylboronic acid derivatives and diol composition, the pH of the solution, and the stereostructure of phenylboronic acid derivatives could influence the interactions between phenylboronic acid derivatives and diol composition. In this study, the factors were evaluated using surface plasmon resonance (SPR). The results show that pH value is an important factor affecting HbA1c and phenylboronic acid to form the complex and Lewis bases. This could change the stereostructure of phenylboronic acid to form B(OH)(3) for binding with saccharine easily. In addition, linear response appeared in HbA1c in the range of 0.43 to 3.49 mug/ml, and the detection limit was 0.01 microg/ml. The results also demonstrated that an SPR biosensor can be used as a sensitive technique for improving the accuracy and correctness of HbA1c measurement.

A urinary microalbumin test is used to detect early signs of kidney damage in people who have a risk of chronic kidney disease, such as those with diabetes or hypertension. In this study, we developed a screen-printed carbon electrode-based immunosensor for the detection of microalbumin in urine. Anti-human albumin antibodies were immobilized on the screen-printed sensor surface by the covalent immobilization method. Cyclic voltammetry (CV) and scanning electron microscopy with an energy dispersive spectroscopical (SEM-EDS) analysis demonstrated that the modification process was well performed. Chronoamperometric (CA) electrochemical measurement technique was employed for the quantitative detection of albumin. The electrochemical measurements performed with some possible interfering compounds normally present in urine (ascorbic acid, uric acid, glucose and creatinine samples) demonstrated a high specificity and selectivity of this immunosensor in albumin detection. Under optimum conditions, the immunosensor can detect urinary albumin in a wide linear range from 10 µg/ml to 300 µg/ml with a detection limit of 9.7 µg/ml. The excellent performance of this immunosensor was confirmed by analyzing microalbumin in urine samples; the results were in good agreement with those obtained by the standard immunoturbidimetric method. The biosensor proposed herein is easy to prepare and can be used for low-cost, rapid, and sensitive screening of microalbuminuria. This approach provides a promising platform for developing clinical point-of-care diagnostic applications.

In this paper, a label free approach of the DNA hybridization detection by the guided-mode resonance (GMR) spectroscopy sensor is presented. The GMR biosensor can easily detect any slight variation of the DNA hybridization by the resonant wavelength peak shift. The corresponding peak wavelength shifts of the capture DNA, the target DNA and the probe DNA serially hybridized reactions from GMR are measured, respectively. Furthermore, the stability and reliability of the GMR biosensor for nucleic acid hybridization have also been examined. The result obviously reveals the feasibility of implementation of the GMR-based DNA microarray for detecting on the dynamics of DNA hybridization.

Purpose: Electrochemical analysis is a powerful tool for analyzing interfacial reactions as well as composition of analytes. In this study, we made a lowcost, portable, and easy-to-use instrument consists of hardware and software for electrochemical analysis. The cost of our design is 1/1000 fold to compare with commercial systems, and the weight of this device is light for 120 grams. Finally, this study used this portable device to detect human serum albumin (HSA) by cyclic voltammetry analysis employing screenprinted carbon electrode (SPCE). Methods: In this study, we made a portable device which consists of hardware and software in it. The hardware part consists of PCB and electrical elements on the PCB. We used ATXmega32A4 as the microcontroller, and TLC2264ID as OP amplifier. The software part was written by C language and compiled with AVR studio. We used homemade instruments to detect HSA with CV with SPCE. All the solutions were prepared at room temperature(25 2 C)and DI water. The concentration of HSA is 0e450 mg/L. Results: Figure shows the CV response of the detection of HSA. With adsorption of HSA on the electrode, we can observe that the peak current decreases when the concentration of HSA increases. This is due to the adsorption of HSA hinders transfer of electrons between electrode and the solution.

Two simple in situ methods, involving the injection of a hyaluronan (HA) solution through a pair of hollow-centred parallel disc electrodes of an electrostatic field system and a micronozzle transducer of an ultrasound atomisation system, were developed and used to prepare HA microspheres in watery phase. The HA microspheres were treated by FeCl 3 and 1-ethyl-3-(3-dimethyl aminopropyl) carbodimide (EDC) to secure the spherical structure shape. Depending on certain treatment conditions, the resulting series of HA microspheres exhibited good sphericity in the range of 317±22 to 579±49±±m in diameter by the electrostatic field system. Stricter conditions were needed to produce HA microspheres by the ultrasound atomisation system because of a viscosity restriction of micronozzle transducer. However, the HA microspheres could be produced and exhibited good sphericity in a smaller size under certain HA concentrations conditions. These prepared HA microspheres had various mechanical durability and could maintain their particulate shape after intra-articular administration of HA microspheres into a rabbit articular cavity for an 11-day period.

The use of interdigitated electrodes and binding with Cibacron blue F3GA by self-assembly technology, which has high affinity for human serum albumin (HSA), and serves as a receptor for HSA detection, is reported. In preliminary tests, the interdigitated chip measured the impedance of HSA by electrochemical impedance spectroscopy and this result indicated the characteristic frequency of impedance change below 1.1 kHz. However, a portable capacitance measurement system made using a standard operational amplifier circuit and AC excitation was applied at 1 kHz. The detection result showed a significant linear correlation between HSA concentration (0.1 to 1 mg/ml) and output voltage. The regression equation was Y 17.91 323.72X with R 2 = 0.999. This reported study has successfully demonstrated that the capacitive sensor has great potential for applications in HSA detection.