RAPID NUTRITIONAL ANALYSIS FROM INFANT TEARS

Nutritional deficiencies in children are currently clinically diagnosed based on recognition of symptoms [7] followed by confirmatory blood tests that take days to complete [8]. The weakness of this approach is that symptom-presentation substantially lags the deficiency, since damage has already occurred. It would be more powerful to ascertain deficiencies well in advance of overt symptoms (i.e. tissue/organ damage). Blood serum levels or urinalysis require milliliters of primary sample and are typically determined by laboratory methods only to verify a diagnosis [8]. This approach is a result of logistical limitations to conventional assays, requiring access to equipment, sample preparation and analysis time. A transformative solution would be a rapid, microliter-volume, diagnostic “lab-on-a-chip” device utilizing tears to assess infant vitamin levels as a near real-time indicator of nutritional health. Lab-on-a-chip (LOC) refers to small (“postage stamp” scale) devices that interrogate drop-sized samples with miniaturized laboratory functions on a single chip. Vitamins are convenient indicators of nutritional health because they are not manufactured by the body and, consequently, reflect the available food sources. The present dissertation discusses the fundamental research behind successfully detecting and identifying vitamins from tears as part of a larger effort to engineer a portable LOC device relying on a minimally invasive biological sample to assess nutrition in infants. The goals of this dissertation are four-fold: a) develop detection protocols compatible with tear samples to quantify infant vitamin levels, b) use these optimized protocols to monitor the vitamin composition of a population of healthy infants, c) study the dependency of infant\u27s nutritional health relative to their parents, and d) adapt this knowledge to conceptually designing a portable LOC device