A hand-held fluorescent sensor platform for selectively estimating green algae and cyanobacteria biomass

This paper reports a portable fluorescent sensor platform containing multiple excitation light illumination for quantification and differentiation of multiple analytes. The fluorescent sensor platform utilizes: (i) three different wavelengths of light emitting diodes (LEDs) for selectively stimulating target analytes; (ii) a sensitive photodetector for corresponding fluorescence measurements; (iii) a custom-built electronic system for data measurement and storage; and (iv) a compact three-dimensional printed housing for the developed sensor platform. Based on the fluorescent emission pattern obtained from each target analyte, multivariate analytical methods were applied to differentiate one analyte from the other in a mixture of multiple analytes. The fluorescent sensor platform was tested to selectively detect two target phytoplankton species: Chlorella vulgaris and Spirulina. Fluorescent emission of phytoplankton is caused by stimulation of photosynthetic pigments and is widely utilized to quantify and classify phytoplankton groups. Biomass estimation was therefore conducted by measuring chlorophyll a fluorescence emission for green algae (Chlorella vulgaris) using blue LED excitation and phycocyanin fluorescence emission for cyanobacteria (Spirulina) using amber LED excitation. The results demonstrated the viability of the developed device as a portable generic fluorescence sensor platform for simultaneously detecting various biochemical analytes. (C) 2018 Elsevier B.V. All rights reserved.