Steady-State Fluorescence of Highly Absorbing Samples in Transmission Geometry: A Simplified Quantitative Approach Considering Reabsorption Events

KRIMER, NICOLÁS I.; RODRIGUES, DARÍO; RODRÍGUEZ, HERNÁN B.; MIRENDA, MARTÍN

ANALYTICAL CHEMISTRY

AMER CHEMICAL SOC

Año: 2017 vol. 89 p. 640 - 647

0003-2700

A simplified methodology to acquire steady-stateemission spectra and quantum yields of highly absorbing samples ispresented. The experimental setup consists of a commercial spectrofluorometeradapted to transmission geometry, allowing the detection ofthe emitted light at 180° with respect to the excitation beam. Theprocedure includes two different mathematical approaches to describeand reproduce the distortions caused by reabsorption on emissionspectra and quantum yields. Toluene solutions of 9,10-diphenylanthracence,DPA, with concentrations ranging between 1.12 × 10−5 and1.30 × 10−2 M, were used to validate the proposed methodology. Thisdye has significant probability of reabsorption and re-emission inconcentrated solutions without showing self-quenching or aggregationphenomena. The results indicate that the reabsorption corrections,applied on molecular emission spectra and quantum yields of the samples, accurately reproduce experimental data. A furtherdiscussion is performed concerning why the re-emitted radiation is not detected in the experiments, even at the highest DPAconcentrations.