Colorimetric Paper-Based Biosensing Device for the Assessment of Bisphenol A in Indoor Dust.

摘要

Objective: The aim of our work was to evaluate a new design for a paper-based sensing device for the colorimetric detection of Bisphenol A (BPA) in household dust. Bisphenol A (BPA) is found in poly-carbonate plastic and epoxy resin and is used in variety a of commercial and consumer products. The leaching of BPA consumer products can result in human exposure via inhalation, ingestion, and dermal routes. As a result, humans have been exposed in their home and work environment to BPA. Several studies have reported detectable levels of total urinary BPA in the majority of individuals in a number of populations, in the United States and other locations around the world. To reduce human exposure we need improved sensing devices to allow for quick, effective and inexpensive screening of our living and working environment. Methods: A rapid procedure for dust collection is used with a sensitive method for BPA detection, based on the formation of a greenish color, on the test zone of the sensing device. The system employs interchangeable low-cost paper-based enzyme sensors as a test zone (0.6 cm in diameter) for BPA detection interfaced with an air-sampling cassette as a sample collection area. The color results from the formation of a Schiff base compound, quinine-imine, formed by reaction of chitosan with the enzymatic product of tyrosinase o-quinone on paper coated in a layer-by-layer (LbL) assembly approach. Colorimetric response was concentration dependent with a detection limit of 0.28 ug/g. The color started to appear within the first 60 s and stabilized after 30 min. Replicate samples were run on a Gas Chromatography (GC) as means of validating the colorimetric data. Field sampling was conducted in a series of homes where dust specimens were collected from different homes and a day care center. Results: Results between the GC and colorimetric sensor showed a linear regression (R2 = 0.9743) for samples measured by both of the colorimetric and GC methods. In this work, BPA ranged in concentration from 0.05 to 3.87 ug/g in 57 samples of household dust when both methods were used. Conclusions: While the sample set was relatively small (n=57), the correlation between the colorimetric sensor and GC method was excellent, thus we feel the sensors is promising as a quick, inexpensive means of measuring BPA in settled dust in the home and work environment.