In order to determine the most appropriate analysis time, ALGPODES beads were prepared with GOx/HRP (as a model reporter) but containing each of the selected chromogenic indicators (ODI, AAP/DHBS, or TMB). Again, three beads of each composition were placed into the cell containing 1 mL of a 0.1 mM glucose solution and their color development was followed capturing pictures every 5 seconds for 600 seconds. The results, summarized in Figure , showed a linear increase in the color intensity for all the dyes during the first minutes of the reaction, approaching a plateau after 200 sec (for AAP/DHBS) and 400 sec (for ODI). Although it was somewhat unexpected (because the H2O2 generated was identical for all experiments), it was observed that the reaction with TMB did not reach a plateau during the investigated time, results than can be attributed to the short reaction time investigated (up to 10 min, while others have reported reading after 15 min 79 -30 min ). In order to balance the sensitivity for the analysis using any of the dyes and considering that a small fraction of AAP/DHBS may leach out of from the beads (as previously discussed), an optimum analysis time of 300 sec was selected and used for all further analyses. Previous reports have described the possibility to used alginate beads as a support to trap other materials (typically hydrophobic) that act as adsorbents and for which controlling the sample volume is essential. Considering this possibility, the color intensity of the ALGPODES beads modified with GOx/HRP-ODI was investigated as a function of the sample volume, in the range between 500 µL and 1500 µL. Again, three beads were placed into the cell, the selected sample volume (containing 0.1 mM glucose) was added and then the color development was followed capturing pictures every 5 seconds for 600 seconds. As summarized in Figure , lower color intensities were observed when the beads were only partially immersed in the sample (< 1000 µL). Beyond that point, the beads totally submerged in the sample and the color intensity was no longer affected by the sample volume, behavior that was attributed to the hydrophilic nature of the target analyte (glucose). Considering these results, a sample volume of 1000 µL was selected as optimum and used for all remaining experiments. and biosensors, one of the critical aspects that remain to be addressed is the sensitivity and practicality of these sensors towards real sample analysis. Towards that goal, the analytical performance of each of the proposed ALGPODES beads (modified with GOx/HRP-ODI, LOx/HRP-AAP/DHBS, or GlutOx/HRP-TMB) was determined against the corresponding target analyte and as a function of concentration. For these experiments, the ALGPODES beads were prepared as previously described, placed in the cell containing 1 mL of the corresponding standard solution and their color development followed with the smartphone for 5 min. Results herein reported correspond to the average and standard deviation of the color intensity obtained with at least 3 beads. As it can be observed (Figure ) the three systems exhibited a similar, sigmoidal response with respect to the concentration, where higher concentrations of each corresponding analyte led to higher color intensities; noting that LOx/HRP-AAP/DHBS showed the best sensitivity, followed by GOx/HRP-ODI and then by GlutOx/HRP-TMB. This trend is in line with the response obtained in paper-based devices using the same enzymes/reporters and can be attributed to the optical response (color intensity) of each of the chromogenic agents. These results were used to calculate the analytical figures of merit for each enzyme/reporter, which are summarized in Table , where the limit of detection (LOD) and limit of quantification (LOQ) were calculated based on the standard deviation of the background noise. and organic acids. In addition, they are dark in color, representing a reasonable challenge for the proposed analytical platform. Thus, the ability of the ALGPODES beads to quantify glutamate, glucose, and lactate in soy sauces samples was evaluated upon a 25-fold dilution with DI water (to match the analytical range). For these experiments, the ALGPODES beads were prepared as previously described, placed in the cell containing 1 mL of the corresponding standard solution and their color development followed with the smartphone for 5 min. Results herein reported correspond to the average and standard deviation of the color intensity obtained with at least 3 beads.