The current quantitative methods of bilirubin have disadvantages such as high cost and low sensitivity. Due to the negative correlation between the level of serum bilirubin and the risk of cardiovascular diseases, a fluorescent ratiometric film sensor was developed aiming at bilirubin detection at low level concentration. Blue-emitting and red-emitting gold nanoclusters were assembled into the same film using layer-by-layer self-assembly technology. Detection of bilirubin was achieved based on the intensity ratio of the two nanoclusters. Bilirubin exposure causes fluorescent quenching of the film. The fluorescence intensity ratio of the two cluster probes had quantitative relationship versus bilirubin concentration. Based on this film sensor, a portable fluorescence detection system was designed for the ratiometric sensing of bilirubin. The hardware of the system was mainly composed of main control chip STM32F407, TSL237 and TSL238T optical frequency sensor. A light-avoiding dark room and detection light path were designed through three-dimensional printing to reduce the interference from ambient light and improve detection accuracy. Experimental results showed that the proposed detection system had strong anti-interference, good stability and accuracy. The linear coefficient of bilirubin detected by this system was 0.987. The system presented good results in reproducible experiments and possessed a good linear relationship with the data obtained by standard spectrofluorometer. The portable system is expected to detect serum bilirubin at low levels.
Bilirubin ; Fluorescence ; Fluorescent Dyes ; Gold ; Metal Nanoparticles ; Spectrometry, Fluorescence/methods*

Humans ; Mercury ; blood ; urine ; Spectrometry, Fluorescence ; methods ; Spectrophotometry, Atomic ; methods

Botryococcus braunii is a unique colonial green microalga and a great potential renewable resource of liquid fuel because of its ability to produce lipids. Due to the dense cell colonies and rigidly thick cell wall of B. braunii, the traditional Nile red method is usually of low sensitivity and bad repeatability and hard for the determination of lipid content in the cells. By dispersing the colony with ultrasonic, assisting permeation of Nile red across the cell wall with dimethyl sulfoxide and optimizing the staining conditions, we established an improved detection method. The details were as follows: after the colonial algal sample was treated by ultrasonic at 20 kHz for 20 s, 100 W transmitting power and with 1 s on/1 s off intermittent cycle, the equivoluminal 15% (V/V) dimethyl sulfoxide and 3 microg/mL Nile red were successively added and mixed evenly, then the staining system was incubated in dark at 40 degrees C for 10 min, and subsequently was measured by fluorescence spectroscopy detection with an excitation wavelength of 490 nm. Compared with the traditional method, the improved one not only had higher detection sensitivity which was increased by 196.6%, but also had obviously better detection repeatability whose characteristic parameter - relative standard deviation (RSD) was decreased from 10.91% to 1.84%. Therefore, the improved method could provide a rapid and sensitive detection of lipid content for B. braunii breeding and cultivation.
Chlorophyta ; chemistry ; Lipids ; analysis ; Microalgae ; chemistry ; Spectrometry, Fluorescence ; methods ; Ultrasonics

We applied two classical algorithms in hyperspectral imaging to extract endmember for biological fluorescence imaging. A combined algorithm was found to initialize the PPI with decreasing the number of multi-spectral pixels, with subsequent N-FINDR refinement, which could make a better result.
Algorithms ; Biology ; methods ; Diagnostic Imaging ; methods ; Image Interpretation, Computer-Assisted ; methods ; Microscopy, Fluorescence ; methods ; Spectrometry, Fluorescence ; methods

OBJECTIVETo develop a new high-performance liquid chromatographic (HLPC) method for determination of propofol in human serum.

METHODSHuman serum samples were precipitated with 20% perchloric acid and centrifuged to obtain 50 microl of the supernatant for analysis by HPLC coupled with fluorescence detection. The analysis was performed with a C(18) reversed-phase column using a acetonitrile-water (90:10) phase delivered at 1.0 ml/min, with the excitation wavelength of 276 nm and emission wavelength of 310 nm.

RESULTSThe calibration curves were linear (r=0.997 5) within the concentration range of 0.05-10 microg/ml, the limit of propofol quantification was 50 ng/ml and the intra- and inter-day precisions were between -/+15%.

CONCLUSIONSThe method is accurate, sensitive and simple for propofol determination in clinical anesthesia.

Anesthetics, Intravenous ; blood ; chemistry ; Chromatography, High Pressure Liquid ; methods ; Fluorescence ; Humans ; Propofol ; blood ; chemistry ; Reproducibility of Results ; Spectrometry, Fluorescence ; methods

The real-time in vivo measurement method has been urgently needed in the research of pharmacokinetics. In the present paper a new in vivo detection method based on fluorescence spectroscopy has been proposed and the monitoring system has been built which is used for pharmacokinetics studies in rats. The relationship between fluorescence intensity and concentration was obtained. By detecting the fluorescent dye Cypate in real-time in rats, the properties of the system have been validated by comparing with the fluorescence imaging system in vitro. The results showed that the system could be feasible for: (1) The linear regression equation of Cypate concentration in the range of 0.098-25 microg/ml is y = 73.249x + 130.97 (R2 = 0.9991 and P < 0.001). RSD of high, medium and low concentration is 1.23%, 6.29% and 13.48%, respectively, and the detecting sensitivity is 0.0981 g/ml; (2) The fluorescent dye concentration from the system is consistent (r = 0.9925) with the fluorescence imaging system in vitro. The fluorescent dye metabolism in rats can be well detected. It can be concluded that a new real-time in vivo detecting method in the paper can be used in pharmacokinetics research.
Animals ; Fluorescent Dyes ; pharmacokinetics ; Rats ; Spectrometry, Fluorescence ; methods ; Spectroscopy, Near-Infrared ; methods

Arsenic ; urine ; Arsenicals ; analysis ; Environmental Monitoring ; methods ; Humans ; Sensitivity and Specificity ; Spectrometry, Fluorescence ; methods

Air Pollutants ; analysis ; Humans ; Industry ; Lead ; analysis ; chemistry ; Spectrometry, Fluorescence ; methods ; Spectrophotometry, Atomic ; methods ; Workplace

Antimony ; urine ; Flow Injection Analysis ; Spectrometry, Fluorescence ; methods ; Spectrophotometry, Atomic ; methods

Humans ; Lead ; urine ; Lead Poisoning ; diagnosis ; urine ; Spectrometry, Fluorescence ; methods ; Spectrophotometry, Atomic ; methods