A paper-based DNA biosensor was developed for food authenticity testing using dairy products as a model. DNA from milk-based samples was isolated, and species-specific DNA sequences were amplified and identified by the biosensor using specific DNA probes. The properties of gold nanoparticles were exploited for visual detection. The biosensor was applied for detection of three species, namely cow, sheep and goat, while as low as 1.6 fmol for cow and goat, and 3.1 fmol for sheep PCR product were detected. Moreover, adulteration down to 0.01% could be detected, based on binary mixtures of cows', ewes' and goats' milk yogurt, containing 0.01 to 5% of cows' yogurt in ewes' and goats' yogurts, respectively. The proposed paper-based DNA biosensor offered 10 times higher detectability than other methods, good specificity and reproducibility, and could be applied easily for the detection of other adulterated food products, such as meat, olive oil and legumes.

中文翻译：

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纸质DNA生物传感器，用于食品真伪测试。

开发了一种基于纸质的DNA生物传感器，以乳制品为模型进行食品真伪测试。从牛奶样品中分离出DNA，并通过生物传感器使用特异性DNA探针扩增和鉴定物种特异性DNA序列。金纳米颗粒的性质被用于视觉检测。该生物传感器用于检测牛，绵羊和山羊这三种物种，而牛和山羊的低至1.6 fmol，绵羊的PCR产物低至3.1 fmol。此外，基于牛，羊和山羊奶酸奶的二元混合物，掺假含量低至0.01％，在牛和羊的酸奶中分别含有0.01至5％的牛酸奶。拟议的纸质DNA生物传感器的可检测性比其他方法高10倍，