A novel on‐chip solution enabling rapid analysis of melamine and chloramphenicol in milk by smartphones

• Published in: Journal of food process engineering 2019-04, Vol.42 (2), p.n/a
• Main Authors: Yang, Ning, Xie, Liang‐Liang, Pan, Chen, Yuan, Min‐Feng, Tao, Zhi‐Han, Mao, Han‐Ping
• Format: Magazinearticle
• Language: English
• ISSN: 0145-8876; 1745-4530
• DOI: 10.1111/jfpe.12976

Ubiquitous food security control is desirable. However, the analysis methods, such as those for milk, are highly based on manual analysis, leading to low efficiency. Thus, we report a multilayer paper‐based microfluidic chip transforming chromatic readout to electric signals. First, colloidal gold immunochromatographic assays (GICA) are used to achieve the colorimetric occurrence. Secondly, the test (T) lines and control (C) lines are patterned to encode different EAN‐8 barcode. Furthermore, accurate scanning is accomplished by the automatic threshold segmentation. These technologies make the digital determination of melamine (MEL) and chloramphenicol (CAP) by phone readily accessible. Results indicate that the accurate machine‐scanning can be assured when MEL and CAP is above 30 ng/mL and 6 ng/mL in milk respectively. The detection time is under 8 min, and the stable storage life is over 90 days. Therefore, this simple chip allows rapid, machine‐readable, electric‐recordable diagnostic directly from chromatic assays with satisfying stability, specificity and accuracy. Practical applications This article illustrates a method used to determine the concentration of melamine and chloramphenicol in milk. When melamine and chloramphenicol is above 30 and 6 ng/ml in milk, the produced EAN‐8 barcode can be recognized with high accurate level, compared with international standards, the results are acceptable and sensitive. This method is highly intellectual and environmentally friendly, with the disposable materials and instant smartphone‐readable EAN‐8 results patterns. This article demonstrates a multilayer paper chip based on EAN‐8 encoding rules, colloidal gold nanoparticles, and immunochromatographic assays. The EAN‐8 format assay is achieved by color‐development occurrence of colloidal GICA in different encoding areas of EAN‐8 code, and the analysis device, namely smartphone, is accessible by almost every individual. Therefore, this chip can pave a potential way for massive health control and digital automated analysis for daily life and industrial manufacture.