- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Colorimetric detection of solution concentration based on a paper-based microfluidic device
摘要： A new method for colorimetric detection of solution concentration is presented. A paper-based micro?uidic device was designed and made using printed circuit board technology. Detection zone patterns were designed and transferred to a printed circuit board by hollowing technology. The printed circuit board with patterns was stuck onto a copper sheet. The hollowed zone was ?lled with solid para?n and then covered with a piece of ?lter paper. The para?n wax was melted by heating the copper sheet and permeated into the ?lter paper. Solution to be detected was pipetted on the paper-based device with detective zones. The images of the detective zones were obtained using a microscope with charge-coupled device, which is used for calculating RGBI model to further obtain the solution concentration. Litmus was demonstrated in sample experiments. Results showed that maximum error of measured value of solution concentration to its true value is less than 2% using the presented method.
关键词： concentration,detective zone,Paper-based device,colorimetric assays
更新于2025-09-09 09:28:46
-
Improving Color Accuracy of Colorimetric Sensors
摘要： Accurate measurements of re?ectance and color require spectrophotometers with prices often exceeding $3000. Recently, new “color instruments” became available with much lower prices, thanks to the availability of inexpensive colorimetric sensors. We investigated the Node+ChromaPro and the Color Muse, launched in 2015 and 2016 by Variable Inc. Both instruments are colorimeters, combining a colorimetric sensor with LED lighting. We investigated color accuracy compared to a high-end spectrophotometer from BYK Gardner. With different sets of samples we ?nd for the Node an average value of dECMC (1:1) = 1.50, and a maximum of 7.86, when comparing with the 45? geometry of the spectrophotometer. Utilizing measurement data on the Spectral Power Distributions of the LEDs, we developed three methods to improve color accuracy as compared to the spectrophotometer data. We used these methods on different sets of samples with various degrees of gloss, both for training the models underlying the methods and for independent tests of model accuracy. Average color accuracy of the Node+ChromaPro improves from dECMC (1:1) = 1.82 to 1.16 with respect to spectrophotometer data. The percentage of samples with dECMC (1:1) < 1.0 increases from 30.9% (uncorrected) to 64%. With the improved color accuracy, these sensors become useful for many more applications.
关键词： measurement accuracy,colorimetric sensor
更新于2025-09-04 15:30:14
-
Colorimetric Analysis of Carcinoembryonic Antigen Using Highly Catalytic Gold Nanoparticles-Decorated MoS <sub/>2</sub> Nanocomposites
摘要： Sensitive detection of carcinoembryonic antigen (CEA) is very important for early detection and cancer therapy monitoring. We utilized the highly catalytic activity of MoS2-gold nanoparticles (MoS2-AuNPs) nanocomposites to construct a colorimetric immunoassay for CEA detection, which could catalyze sodium borohydride (NaBH4) to reduce 4-nitrophenol (4-NP) and make the yellow solution colorless. MoS2-AuNPs nanocomposites could e?ciently load antibodies (Ab1 and Ab2) because of their good biocompatibility and high adsorption ability, forming Ab1-MoS2-AuNPs nanoprobes for capturing CEA and Ab2-MoS2-AuNPs nanoprobes for catalytic reaction. It should be pointed out that Ab2-MoS2-AuNPs nanoprobes retained high catalytic activity because no blocking agent was used to block the catalytic sites. After the formation of the classical “sandwich” structure, parts of Ab2-MoS2-AuNPs nanoprobes remained in the supernatant after centrifugation, making the catalytic reaction occur and obtaining a colorless solution. As expected, a linear function between absorbance peak intensity and the logarithm of 5 pg/mL?10 ng/mL CEA was observed, and the detection limit was obtained as 0.5 pg/mL. This colorimetric immunosensor showed acceptable selectivity and repeatability for CEA detection, which could be successfully employed to detect CEA in serum.
关键词： nanoprobe,colorimetric,carcinoembryonic antigen,molybdenum disul?de,immunosensor
更新于2025-09-04 15:30:14
-
[IEEE 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Effect of thermal and electrical stress on photometric, radiometric, and colorimetric characteristics of large area white organic light emitting diodes
摘要： The aim of this paper is to identify the photometric, radiometric, and colorimetric signatures of degradations of large area white organic light emitting diodes (Philips GL55, 41cm2 active area), subjected to various stress conditions. Nine devices have been stressed at a constant current density of 11.25mA/cm2, 13mA/cm2 and 15mA/cm2 at 23°C (room temperature), 40°C and 60°C. We have also stocked three devices under purely thermal stress at the same temperatures. Thus, we can make comparison between electrical-thermal stress and purely thermal stress. Over aging time, an increase of both the correlated color temperature and the general rendering index was observed. The degradation rate of the blue emitter is more significant than the other emitters, which induced a color shift toward a green-yellow.
关键词： OLED,thermal stress,colorimetric characterization,electrical stress,degradation signature,aging
更新于2025-09-04 15:30:14
-
Intrinsically Porous Dual-Responsive Polydiacetylenes Based on Tetrahedral Diacetylenes
摘要： The combinatorial functionalization in a single molecular framework by structural integration utilizing multiple functional materials to create prede?ned structural morphology and multistimuli-responsive smart materials has attracted intensive attention. Herein, we constructed intrinsically porous and dual-responsive supramolecule, TeDA, by introducing a photopolymerizable diacetylene template (10,12-pentacosadiynoic acid) to the sterically rigid tetrahedral tetraphenylmethane (TPM) core. The self-assembled monomeric TeDA is transformed into the covalently cross-linked blue-phase polydiacetylene (TePDA) by UV irradiation (UV 254 nm). The BET measurement and examination of SEM images con?rm the mesoporous characteristic for TeDA/PDA. Very interestingly, the blue-phase TePDA produces a naked-eye detectable colorimetric response to heat and VOCs (liquid and vapor phase). Most importantly, TePDA exhibits reversible thermochromism and excellent colorimetric response to chloroform vapors. To signify the structural in?uence of TPM on material properties, we also studied non-TPM derivatives. The TeDA/PDA integrated system demonstrates potential applications in developing multistimuli-responsive sensors.
关键词： dual-responsive,porous,thermochromism,VOCs detection,colorimetric response,polydiacetylenes,tetrahedral diacetylenes
更新于2025-09-04 15:30:14
-
Colorimetric Sensor Array for Monitoring CO and Ethylene
摘要： Developing miniaturized and inexpensive detectors remains an important and practical goal for field-deployable monitoring of toxic gases and other bioactive volatiles. CO (a common toxic pollutant) and ethylene (the phytohormone primarily responsible for fruit ripening) share the capability of strong back-π-bonding to low-oxidation-state metal ions, which has proved important in the development of metal-ion-based sensors for these gases. We report herein cumulative colorimetric sensor arrays based on Pd(II)-silica porous microsphere sensors and their application as an optoelectronic nose for rapid colorimetric quantification of airborne CO and ethylene. Quantitative analysis of two gases was obtained in the range of 0.5 to 50 ppm with detection limits at the sub-parts-per-million level (～0.4 ppm) after 2 min of exposure and ～0.2 ppm after 20 min (i.e., <0.5% of the permissible exposure limit for CO and <10% of the ethylene concentration needed for fruit ripening). We further validate that common potential interfering agents (e.g., changes in humidity or other similar air pollutants such as NOx, SO2, H2S, or acetylene) are not misidentified with CO or ethylene. Finally, the sensor is successfully used for the quantification of ethylene emitted from ripening bananas, demonstrating its potential applications in the monitoring of fruit ripening during storage.
关键词： Pd(II)-silica porous microsphere sensors,CO,ethylene,colorimetric sensor array,optoelectronic nose
更新于2025-09-04 15:30:14