Polychlorinated biphenyl detection in organic solvents with paper-based analytical devices

ABSTRACT

Sample pretreatment process is usually performed before real sample detection. Extraction is one of the most prevalent pretreatment methods. Due to the unequal solubility in two liquid phases, target is extracted (usually from water to organic phase) and further detected with laboratory instruments. Although the analytical instruments have high sensitivity and selectivity, they are relatively expensive and require skilful hands, which is restricted to laboratory use. Here, paper-based analytical devices (μPADs) for measuring samples extracted with organic solvents were tested. The μPADs were employed as a filter for buffer exchange, allowing the transfer of targets from organic solvent to water-based buffer, which could be specifically detected by water-based assays. As an example, polychlorinated biphenyls (PCBs) in n-hexane were detected with aptamer and gold nanoparticles (AuNPs) on μPADs within 30 min. The result of colour change can be recognized from 70.0 ng/L with a low loading amount (0.5 μL). Instead of laboratory instrumental analysis with relative high cost, this assay showed the promising utility of μPADs for target detection after sample pretreatment, which could be utilized as a general platform for inexpensive onsite detection.

GRAPHICAL ABSTRACT

KEYWORDS:

• Polychlorinated biphenyls (PCBs)
• organic solvents
• μPADs
• onsite detection
• gold nanoparticle

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [grant number 51808378] and the Research Fund of Tianjin Key Laboratory of Aquatic Science and Technology [grant numbers TJKLAST-PT-2017-03, TJKLAST-PT-2018-03 and TJKLAST-PT-2018-04]