2026-10-14T03:25:52Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34028764 2026-09-30T03:07:29Z category_4 category_146 category_7 category_21 category_873 category_39 category_734 category_69 category_133 portal_63 item_type_6 month_year_09_2026

A Microdroplet Fluorescence Method for the Determination of Nitrite in Water Using a Hydrophobic Cellulose Substrate Platform Júlia C. Romero (25139974) Vanesa Romero (1812901) Carlos Bendicho (1812904) Fábio A. C. Amorim (25139977) Biochemistry Space Science Medicine Biotechnology Chemical Sciences not elsewhere classified Ecology Biological Sciences not elsewhere classified Inorganic Chemistry Plant Biology various natural waters suspends stable microdroplets signal attenuation inherent relative standard deviation reduce reagent consumption nonwettable cellulose substrate enabling direct measurement cellulose substrate acted 35 μg l 17 μg l fluorescence signal acquisition total reaction volume conventional laboratory assays based environmental monitoring microdroplet fluorescence method microdroplet suspension water samples values obtained trace amounts successfully applied solid support sensitive alternative rsd %), recoveries ranging n </ microliter scale innovation consists front surface fluorimetric reaction environmentally friendly cost alternative concentrations relevant agreeprep score acid medium 7 ). 15 μl 115 %. In this work, a miniaturized and sustainable method was developed, based on the fluorimetric reaction with 2,3-diaminonaphthalene (DAN) in an acid medium, for the determination of trace amounts of nitrite in different water samples using a hydrophobic cellulose substrate platform. The innovation consists of the use of a nonwettable cellulose substrate that suspends stable microdroplets, enabling direct measurement of fluorescence on the front surface and mitigating the signal attenuation inherent in traditional hydrophilic paper devices. The cellulose substrate acted both as a solid support for the reaction and as a holder for microdroplet suspension during fluorescence signal acquisition. The method was designed to reduce reagent consumption and waste generation by operating at the microliter scale, using a total reaction volume of 15 μL. The procedure showed great tolerance to the presence of 11 potentially interfering ions, evaluated at concentrations relevant to water samples. The values obtained for the limit of detection were 0.35 μg L^–1, the limit of quantification was 1.17 μg L^–1. The precision, based on the relative standard deviation (RSD%), was 3.5% (<i>N</i> = 7). The method was successfully applied to various natural waters, with recoveries ranging from 83 to 115%. With an AGREEprep score of 0.77, the procedure significantly reduces reagent consumption and waste, offering an environmentally friendly and low-cost alternative to conventional laboratory assays and providing a simple and sensitive alternative for laboratory-based environmental monitoring of nitrite. 2026-09-29T00:00:00Z Text Journal contribution 10.1021/acsomega.6c06452.s001 https://figshare.com/articles/journal_contribution/A_Microdroplet_Fluorescence_Method_for_the_Determination_of_Nitrite_in_Water_Using_a_Hydrophobic_Cellulose_Substrate_Platform/34028764 CC BY-NC 4.0