Lipowicz Michelle, Garcia Antonio
School of Biological and Health Systems Engineering, Ira A. Fulton Schools of Engineering, Arizona State University, Tempe, AZ 85287, USA.
Bioengineering (Basel). 2015 Jun 2;2(2):122-138. doi: 10.3390/bioengineering2020122.
The use of saliva sampling as a minimally-invasive means for drug testing and monitoring physiology is a subject of great interest to researchers and clinicians. This study describes a new optical method based on non-axially symmetric focusing of light using an oblate spheroid sample chamber. The device is simple, lightweight, low cost and is easily attached to several different brands/models of smartphones (Apple, Samsung, HTC and Nokia) for the measurement of sodium ion levels at physiologically-relevant saliva concentrations. The sample and fluorescent reagent solutions are placed in a specially-designed, lightweight device that excludes ambient light and concentrates 470-nm excitation light, from a low-power photodiode, within the sample through non-axially-symmetric refraction. The study found that smartphone cameras and post-image processing quantitated sodium ion concentration in water over the range of 0.5-10 mM, yielding best-fit regressions of the data that agree well with a data regression of microplate luminometer results. The data suggest that fluorescence can be used for the measurement of salivary sodium ion concentrations in low-resource or point-of-care settings. With further fluorescent assay testing, the device may find application in a variety of enzymatic or chemical assays.
将唾液采样作为药物检测和生理监测的一种微创手段，是研究人员和临床医生非常感兴趣的课题。本研究描述了一种基于使用扁球体样品室进行非轴对称光聚焦的新型光学方法。该设备简单、轻便、成本低，并且易于连接到几种不同品牌/型号的智能手机（苹果、三星、HTC和诺基亚），用于测量生理相关唾液浓度下的钠离子水平。样品和荧光试剂溶液放置在一个特别设计的轻便设备中，该设备可排除环境光，并通过非轴对称折射将来自低功率光电二极管的470纳米激发光集中在样品内。研究发现，智能手机摄像头和图像后处理可对0.5-10 mM范围内水中的钠离子浓度进行定量，得出的数据最佳拟合回归与微孔板发光计结果的数据回归非常吻合。数据表明，荧光可用于在资源匮乏或即时护理环境中测量唾液钠离子浓度。通过进一步的荧光测定测试，该设备可能会在各种酶促或化学测定中得到应用。
