Inkjet-assisted layer-by-layer printing of quantum dot/enzyme microarrays for highly sensitive detection of organophosphorous pesticides

• The large scale microarrays of CdTe QDs and AChE were fabricated by facile inkjet-assisted LbL printing technique.
• The QDs/AChE microscopic dot arrays could be used quantitatively and rapidly for the sensitively visual detection of OPs.
• A detection limit of 10 μg L−1 was achieved, much lower than levels specified by standard tests and other colorimetric detection methods.
• The low cost, short processing time, sufficient sensitivity, good stability and ease of use make it for a facile platform for on-site screening.

We present a facile fabrication of layer-by-layer (LbL) microarrays of quantum dots (QDs) and acetylcholinesterase enzyme (AChE). The resulting arrays had several unique properties, such as low cost, high integration and excellent flexibility and time–saving. The presence of organophosphorous pesticides (OPs) can inhibit the AChE activity and thus changes the fluorescent intensity of QDs/AChE microscopic dot arrays. Therefore, the QDs/AChE microscopic dot arrays were used for the sensitive visual detection of OPs. Linear calibration for parathion and paraoxon was obtained in the range of 5–100 μg L−1 under the optimized conditions with the limit of detection (LOD) of 10 μg L−1. The arrays have been successfully used for detection of OPs in fruits and water real samples. The new array was validated by comparison with conventional high performance liquid chromatography-mass spectrometry (HPLC-MS).

A fluorimetric assay for high-throughput screening of organophosphorous pesticides was developed based on the CdTe QDs/AChE microarrays via inkjet-assisted LbL printing techniques.Figure optionsDownload as PowerPoint slide