Conventional analytical techniques, which have been developed for high sensitivity and selectivity for the detection and quantification of relevant biomarkers, may not be as suitable for medical diagnosis in resource scarce environments as compared to point-of-care devices (POC). We have developed a new reactive sensing material which contains ionic gold entrapped within an agarose gel scaffold for POC quantification of ascorbic acid (AA) in tear fluid. Pathologically elevated concentration of AA in human tear fluid can serve as a biomarker for full-thickness injuries to the ocular surface, which are a medical emergency. This reactive sensing material will undergo colorimetric changes, quantitatively dependent on endogenous bio-reductants that are applied, as the entrapped ionic gold is reduced to form plasmonic nanoparticles. The capacity for this reactive material to function as a plasmonically driven biosensor, called ‘OjoGel’ (ojo-eye), was demonstrated with the endogenous reducing agent, AA. Through applications of AA of varied concentrations to the OjoGel, we demonstrated a quantitative colorimetric relationship between red (R) hexadecimal values and concentrations of AA in said treatments. This colorimetric relationship is directly resultant of plasmonic gold nanoparticle formation within the OjoGel scaffold. Using a commercially available mobile phone-based Pixel Picker^® application, the OjoGel plasmonic sensing platform opens a new avenue for easy-to-use, rapid, and quantitative biosensing with low cost and accurate results.

与现场护理设备（POC）相比，针对检测和定量相关生物标记物的高灵敏度和选择性而开发的常规分析技术可能不适合在资源匮乏的环境中进行医学诊断。我们已经开发了一种新的反应性传感材料，其中包含包裹在琼脂糖凝胶支架中的离子金，用于泪液中抗坏血酸（AA）的POC定量。病理性升高的人类泪液中的AA浓度可作为眼表全层损伤的生物标记物，这是医疗急症。这种反应性传感材料将发生色度变化，定量地取决于所应用的内源性生物还原剂，因为被夹带的离子金被还原形成等离激元纳米颗粒。内源性还原剂AA证明了这种反应性材料具有被称为'OjoGel'（ojo-eye）的等离激元驱动的生物传感器的功能。通过将不同浓度的AA应用于OjoGel，我们证明了在上述处理中，红色（R）十六进制值与AA浓度之间存在定量比色关系。这种比色关系是OjoGel支架内等离子金纳米颗粒形成的直接结果。使用市售的基于手机的Pixel Picker 我们证明了在上述处理中红色（R）十六进制值与AA浓度之间存在定量比色关系。这种比色关系是OjoGel支架内等离子金纳米颗粒形成的直接结果。使用市售的基于手机的Pixel Picker 我们证明了在上述处理中红色（R）十六进制值与AA浓度之间存在定量比色关系。这种比色关系是OjoGel支架内等离子金纳米颗粒形成的直接结果。使用市售的基于手机的Pixel Picker^®应用，OjoGel等离子体传感平台为低成本，准确结果的易于使用，快速和定量的生物传感开辟了一条新途径。