Dipsticks integrated on smart diapers for colorimetric analysis of urinary tract infections in the field

Urinary tract infections (UTI) are common infection diseases in the hospitals, affecting especially elderly people. Detecting UTI from samples obtained from elderly persons is difficult and time-consuming procedure. Although the current commercial dipsticks are relatively easy to use and work well with large-volume urine samples, they are difficult to use in diapers, where the urine is highly absorbed. Diapers have been envisaged as an ideal method to easily collect samples from elderly persons. In this regard, this paper introduces a new approach to detect UTI markers from used diapers. To demonstrate the feasibility of the proposed method, commercial dipsticks were incorporated within the diapers, and three UTI markers were detected in urine samples previously deposited on those smart diapers. The results of the dipstick tests showed no significant difference between integrating the dipsticks within the diaper and testing the dipsticks in beakers with urine. Furthermore, the results were consistent between different concentrations (10⁵ to 10⁹ CFU/ml) of E. coli cells, the major UTI agent, spiked into the urine samples. This method holds promises for not only elderly persons, but also adults, especially women, even pets that could have UTI. The concept of smart diaper can also be extended to sanitary towel and pet pad.