This paper presents a miniature and cost-effective cell fiber-spectrophotometer based on fluorescence emission sensing for real-time detection of biomarkers The prototype comprises a highly sensitive spectrometer embedded in an inexpensive 3D-printed housing and a custom-designed printed circuit board to transmit the data wirelessly Results show that this portable system can identify micro-volume samples of tubulin protein, a well-known biomarker, to study different types of cancer Additionally, our ambulatory prototype is small in size (30 mm &#x00D7;24 mm &#x00D7;43 mm), lightweight (19 g), economical, and low-power (103 mW) Fluorescence spectrophotometry measurement results obtained in vitro for stained VERO E6 cells using the presented prototype are reported A set of samples with varying concentrations of Alexa Fluor 488 were also tested, and their spectral responses were measured within the range of 340&#x2013;850 nm with a resolution of 15 nm The measured limits of quantification and detection are 20 and 4 &#x03BC;g/mL, respectively, while the measured responsivity is 85 mV/nW with a minimum detectable power of 117 fW at 519 nm Intra- and inter-day relative standard deviations of 1 5% and 4 7%, respectively, were measured during longitudinal sensitivity experiments IEEE
Miniature Fiber-Spectrophotometer for Real-Time Biomarkers Detection