Urinary albumin excretion remains the key biomarker to detect renal complications in type 2 diabetes. As diabetes epidemy increases, particularly in low-income countries, efficient and low-cost methods to measure urinary albumin are needed. In this pilot study, we evaluated the performance of Raman spectroscopy in the assessment of urinary albumin in patients with type 2 diabetes. The spectral Raman analysis of albumin was performed using artificial urine, at five concentrations of albumin and 24 h collection urine samples from ten patients with Type 2 Diabetes. The spectra were obtained after removing the background fluorescence and fitting Gaussian curves to spectral regions containing features of such metabolites. In the samples from patients with type 2 diabetes, we identified the presence of albumin in the peaks of the spectrum located at 663.07, 993.43, 1021.43, 1235.28, 1429.91 and 1633.91 cm⁻¹. In artificial urine, there was an increase in the intensity of the Raman signal at 1450 cm⁻¹, which corresponds to the increment of the concentrations of albumin. The highest concentration of albumin was located at 1630 cm⁻¹. The capability of Raman spectroscopy for detection of small concentrations of urinary albumin suggests the feasibility of this method for the screening of type 2 diabetes renal complications.

We designed and built a homemade computed tomography imaging spectrometer (CTIS) of 250 × 250 p i x e l s of spatial resolution and 2 nm spectral resolution. The optical design considers a CTIS optical array coupled to a digital reflex camera. We reconstructed the intensity spectra of a fluorescent source, the diffuse reflectance of a ColorChecker, and samples of Capsicum annuum of three different colors, using the expectation-maximization sequential algorithm, optimized utilizing an array of indices to reduce the reconstruction time. The results obtained with a ColorChecker indicate a high positive correlation of 0.9745 with an average residual difference of 1.31% concerning the spectra obtained with a commercial integrating sphere spectrometer. The feasibility of the proposed CTIS system shows how to detect and evaluate the physiological changes resulting from the decomposition of the green fruit of the Capsicum annuum in a range from 500 to 650 nm.