This study was to develop a new method for detecting circulating tumor cells (CTCs) with high sensitivity and specificity, therefore to detect the colorectal cancer as early as possible for improving the detection rate of the disease. To this end, we prepared some micro-column structure microchips modified with graphite oxide-streptavidin (GO-SA) on the surface of microchips, further coupled with a broad-spectrum primary antibody (antibody1, Ab₁), anti-epithelial cell adhesion molecule (anti-EpCAM) monoclonal antibody to capture CTCs. Besides, carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were coupled with colorectal cancer related antibody as specific antibody 2 (Ab₂) to prepare complex. The sandwich structure consisting of Ab₁-CTCs-Ab₂ was constructed by the microchip for capturing CTCs. And the electrochemical workstation was used to detect and verify its high sensitivity and specificity. Results showed that the combination of immunosensor and micro-nano technology has greatly improved the detection sensitivity and specificity of the immunosensor. And we also verified the feasibility of the immunosensor for clinical blood sample detection, and successfully recognitized detection and quantization of CTCs in peripheral blood of colorectal cancer patients by this immunosensor. In conclusion, the super sandwich immunosensor based on micro-nano technology provides a new way for the detection of CTCs, which has potential application value in clinical diagnosis and real-time monitoring of disease.
Humans ; Nanotubes, Carbon/chemistry* ; Neoplastic Cells, Circulating/pathology* ; Biosensing Techniques ; Immunoassay/methods* ; Antibodies ; Colorectal Neoplasms/diagnosis* ; Electrochemical Techniques/methods* ; Gold/chemistry*

Exosomes are phospholipid bilayer membrane-enclosed vesicles released from cells with diameters of 30-150 nm, exosomes can directly reflect the physiological and functional state of secretory cells, participate in material transport and information communication between cells, which are of great significance as biomarkers for early tumor diagnosis and treatment evaluation. There are many detection methods for exosomes, among which aptasensor technology with the properties of low price and easy operation, fast response, high sensitivity, remarkable specificity helps tumor patients to find, diagnose and treat early, improve the survival rate, and provide important basis for the evaluation of the prognosis. There are seven types of common aptasensors: fluorescent, electrochemical, colorimetric, luminescence, lateral flow strips, surface-enhanced Raman scattering and surface plasmon resonance sensors. Different aptasensors have different characteristics, this article focuses on the research progress of several common aptasensor for tumor exosomes detection.
Humans ; Exosomes/metabolism* ; Biomarkers/analysis* ; Neoplasms/diagnosis* ; Phospholipids/metabolism* ; Biosensing Techniques/methods*

Synthetic biology aims to endow living cells with new functions by incorporating functional gene networks into them. By overexpressing, blocking and rewiring native gene pathways, synthetic biologists have harnessed this promising technology to reprogram cells to perform diverse tasks such as drug discovery, biopharmaceutical manufacturing, gene therapy and tissue engineering, etc. In this review, we focus on current technologies of synthetic biosensors for disease detection. We start with the design principle of synthetic biosensors. Then we move towards the characteristics of simple synthetic biosensors, which can respond to a single input signal, and complex synthetic biosensors including Boolean gate biosensors, cascade biosensors, time-delay biosensors, oscillator biosensors and hysteretic biosensors, which can respond to more than two input signals and perform complex tasks. Synthetic biosensor has showed great potential in disease detection, but it is still in its infancy stage. More efforts should be made in identifying and constructing clinically relevant regulation systems. Computational tools are also needed in the design process in order to guarantee the precision of the synthetic biosensor. The ultimate goal of a synthetic biosensor is to act as a therapeutic sensor-effector device that connects diagnostic input with therapeutic output and therefore provides all-in-one diagnostic and therapeutic solutions for future gene- and cell-based therapies.
Biosensing Techniques ; methods ; Humans ; Synthetic Biology ; methods

The study is to report the establishment of a method of screening the antitumor compounds based on the dynamic bio-response profile of cells to make up for the shortages of conventional end-point tests such as tedious operation and low sensitivity. Based on the principle of electric impedance of cells, the real-time cell electronic sensing (RT-CES) system was used to monitor the effect of epirubicin (EPI), cisplatinum (DDP) and carboplatin (CBP) on the growth of HepG2 cells, with the cell index (CI), half maximal inhibitory concentration (IC50) and detachment curve as evaluation indexes. Meanwhile, cell counting kit-8 (CCK-8) and microscopy were applied for verification. The results showed that CI curve could sensitively real-time profile the inhibitory effect of model drugs on HepG2 cells. The IC50 of EPI, DDP and CBP were 0.53 +/- 0.04, 9.79 +/- 0.26 and 597.00 +/- 3.79 microg x mL(-1), respectively. What's more, the significant differences of detachment curves of the three drugs indicated that their functional mechanisms might be different, this is consistent with the literature. The RT-CES system with non-invasive, label-free and real-time characteristics could be used to monitor the bio-response profile of the three drugs to HepG2 cells, allowing to qualitatively and quantitatively distinguish the antitumor activities of the three drugs, and could be a complementary method for the present screening of antitumor compounds.
Antineoplastic Agents ; pharmacology ; Biosensing Techniques ; methods ; Cell Count ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Drug Screening Assays, Antitumor ; Electric Impedance ; Humans

BACKGROUND: The Hb levels of prospective blood donors are usually determined using a finger prick test. A new noninvasive Hb device has the advantage of not causing any sampling pain. The purpose of this study was to evaluate the accuracy of the noninvasive Hb sensor and to compare its measurements with those of a currently used portable hemoglobinometer. METHODS: Hb was measured using a noninvasive Hb sensor (NBM-200; OrSense, Israel), a portable hemoglobinometer (HemoCue; HemoCue AB, Sweden), and an automated hematology analyzer (LH500; Beckman Coulter, USA). The correlations between Hb measurements taken by the NBM-200 and HemoCue with those by an automated hematology analyzer were assessed using intraclass correlation coefficients (ICCs). Hb measurements were compared among 3 different Hb level groups. RESULTS: The mean Hb values of 506 blood donors were 14.1 g/dL by the NBM-200, 14.0 g/dL by the LH500, and 14.3 g/dL by the HemoCue. The correlation between the LH500 and the NBM-200 was substantial (ICC=0.69), while that between the LH500 and the HemoCue agreed almost perfectly (ICC=0.86). CONCLUSIONS: The possibility to judge to be eligible for donors who are ineligible to donate was substantial when using NBM-200. Even though the NBM-200 has the apparent advantage of noninvasiveness, its use in pre-screening should be given meticulous attention. Since pre-donation testing is crucial to protecting donors' health, complete evaluation of the instrument should be performed prior to use.
Automation ; Biosensing Techniques/*instrumentation ; Blood Chemical Analysis/*instrumentation ; Blood Donors ; Donor Selection/*methods ; Female ; Hemoglobins/*analysis ; Humans ; Male ; Sensitivity and Specificity

Optimization of sensor array is a significant topic in the application of electronic nose (EN). Stepwise discriminant analysis and cluster analysis combining with screening of typical index were employed to optimize the original array in the classification of 100 samples from 10 kinds of traditional Chinese medicine based on alpha-FOX3000 EN. And the identification ability was evaluated by three algorithm including principle component analysis, Fisher discriminant analysis and random forest. The results showed that the identification ability of EN was improved since not only the effective information was maintained but also the redundant one was eliminated by the optimized array. The optimized method was eventually established, it was accurate and efficient. And the optimized array was built up, that is, S1, S2, S5, S6, S8, S12.
Algorithms ; Biosensing Techniques ; methods ; Cluster Analysis ; Discriminant Analysis ; Drugs, Chinese Herbal ; classification ; isolation & purification ; Electronic Nose ; Medicine, Chinese Traditional ; Principal Component Analysis ; Reproducibility of Results ; Smell

OBJECTIVETo investigate the use of the electronic tongue in the evaluation of traditional Chinese medicinal materials with sour, bitter, sweet or salty tastes, and assess the possible application of the sensor in the evaluation of different tastes of traditional Chinese medicinal materials.

METHODAqueous extracts of 22 traditional Chinese medicinal materials were measured by the electronic tongue. The data collected with the tongue was evaluated for discrimination of the samples with multivariate statistical methods: principal component analysis (PCA) and discriminant factor analysis (DFA).

RESULTThe electronic tongue was capable of discriminating between samples with different taste modalities and could also distinguish different samples eliciting the same basic taste. Twenty-two traditional Chinese medicinal materials could be classified into five clusters based on PCA. These differences seem to derive from the different tastes. DFA was applied to construct a model to discriminate traditional Chinese medicinal materials with different tastes. And the samples yielded about 88.2% accuracy for cross-validation.

CONCLUSIONWe confirmed that the electronic tongue may provide an analytical procedure for classification of the samples with respect to tastes of the traditional Chinese medicinal materials.

Biosensing Techniques ; instrumentation ; methods ; Cluster Analysis ; Discriminant Analysis ; Drugs, Chinese Herbal ; isolation & purification ; Electrical Equipment and Supplies ; Medicine, Chinese Traditional ; Models, Theoretical ; Multivariate Analysis ; Principal Component Analysis ; Reproducibility of Results ; Taste

Conducting polymers have stable long-chain structure and good electrical conductivity. They have been used in various types of biosensors because of their excellent characteristics of the immobilization and electrical signal transmission. In recent years, researchers mainly study on improving its micro-nano structures and its signal conductivity to enhance its effect on the enzyme immobilization and signal conductive properties. This paper reviews firstly the application of conducting polymer on enzyme-immobilized glucose biosensor and the new technologies and methods in this field. This paper also points out the future application of conducting polymers in enzyme immobilization and biosensor preparation areas.
Biosensing Techniques ; methods ; trends ; Blood Glucose ; metabolism ; Electric Conductivity ; Enzymes, Immobilized ; Glucose Oxidase ; metabolism ; Nanostructures ; Polymers ; chemistry

We studied the interaction between proteins and polystyrene-polyacrylic acid (PS-PAA) spherical polyelectrolyte brushes with different polyacrylic acid (PAA) chain lengths, including the physical adsorption and chemical adsorption in PBS buffer. Results showed that the amount of bovine serum albumin (BSA) physically adsorbed on PS-PAA spherical polyelectrolyte brushes decreased to a minimum of 33 microg/mg whereas the amount of streptavidin (SA) chemically adsorbed increased with the increase of chain length and carboxyl quantity. The biotin binding capacity of streptavidin chemically adsorbed on PS-PAA spherical polyelectrolyte brushes was roughly evaluated via enzyme competitive inhibition.
Acrylic Resins ; chemistry ; Adsorption ; Biosensing Techniques ; Electrochemical Techniques ; methods ; Electrolytes ; chemistry ; Polyamines ; Polymers ; chemistry ; Polystyrenes ; chemistry ; Proteins ; chemistry ; Serum Albumin, Bovine ; chemistry ; Surface Properties

The foot drop functional electrical stimulation (FES) system consisting of various sensors has been widely applied to the disease of the foot drop. However, the current system is limited to the research on walking on the ground and ignores other important actions of foot in one's daily life, such as walking up and down the stairs, squatting and lying down, etc. In this work, we applied the dual axis angle sensor to the system of the foot drop FES for the first time. Such a system can not only stimulate the foot drop during normal walking, but also identify squatting, sitting, and lying down etc. and furthermore, the system can switch off automatically. In the meanwhile, it can also detect falls and other dangerous actions. The accuracy of our system can achieve 100%, 81.9%, 95.8%, 99.0% and 66.9% for normal walking, sitting-standing, walking up the stairs, walking down the stairs and squatting-standing respectively.
Adult ; Biosensing Techniques ; instrumentation ; methods ; Electric Stimulation ; instrumentation ; methods ; Equipment Design ; Female ; Foot Deformities, Acquired ; therapy ; Humans ; Male ; Middle Aged ; Young Adult