A concept of dual optical detection using three light emitting diodes

Simultaneous Colorimetric Measurements of Antioxidant Capacity by Flow Injection Analysis with Paired Emitter Detector Diode

“…Koncki et al reported the use of LEDs for both absorption and fluorescence measurement. 25,26 The PEDD has been employed in the analysis of physiological samples, [27][28][29][30][31][32][33][34][35][36][37][38][39][40] drink and food samples [41][42][43][44] and environmental samples. 45 There are also reports of dual analysis employing PEDDs, for example, multicommutated flow (MCFA) system for the determination of activity of acid phosphate and alkaline phosphatase, 46 sequential injection (SI) system for quantitative measurement of sucrose and phosphate, 47 MCFA system for determination of phosphate and calcium, 48 MCFA system for total protein and creatinine analysis 49 and MCFA system for investigation of iron-transferrin and apotransferrin speciation in human serum.…”

Towards optoelectronic urea biosensors

“…The first analytical PEDDs have been developed for photometric measurements as dedicated, economic, and miniaturized optoelectronic devices useful for conventional measurement with the use of cuvettes as well as for the use in flow analysis format (dedicated flow-through detectors for flow injection analysis (FIA), SIA, MCFA, and HPLC). Such photometric devices have been successfully applied for determination of selected metal ions [ 1 – 9 ], ammonia [ 10 ], inorganic anions [ 11 – 15 ], total organics [ 16 ], quinine [ 17 ], hemoglobin [ 18 ], creatinine [ 19 ], and proteins [ 20 ] as well as for enzyme activity assays [ 21 – 23 ]. Only recently, Nwankire et al [ 24 ] have reported on PEDD-based microfluidic analysis system allowing blood assay of five analytes important for liver diagnostics (albumin, total and direct bilirubin, alkaline phosphatase, and γ-glutaral transferase).…”

“…Our research group has demonstrated that PEDDs can be also configured as complete and effective fluorimetric detectors consisting of integrated LED inductor and LED detector of fluorescence [ 17 , 25 ]. Such approach is possible because LEDs are found to be partially selective detectors able to detect fluorescence emission with negligible effects from the exciting light.…”

“…Such approach is possible because LEDs are found to be partially selective detectors able to detect fluorescence emission with negligible effects from the exciting light. Until now, two and three LED-based fluorimetric detectors have been successfully developed for determination of calcium [ 25 , 26 ] and phosphate [ 14 , 15 ] ions, quinine [ 17 ], vitamin B [ 27 ], and proteins [ 20 ]. Only recently, turbidimetric [ 28 – 31 ] and nephelometric [ 30 , 31 ] detectors operating according to PEDD principle have been reported.…”

A fluorometer on the basis of powerful light emitting diodes for determination of the chlorophyll “a” concentration

“…The design of a fluorometer for the determination of inten sively fluorescent quinine based on three LEDs with out additional optoelectronic components was devel oped in [12], and the application area of the scheme was extended and described in detail in [13]. The com bination of LEDs for excitation and registration of the fluorescence signal allows extreme simplification of the fluorometer scheme eliminating primary and sec ondary filters that decrease the intensity of the excita tion and emission signals, decrease its dimensions, and provide the possibility of an in house detector design [13].…”