Paper-based enzyme free platform for detecting falsified antibiotics using gold nanoparticles

The emergence of counterfeit and substandard medicines is a worldwide problem that has been growing over the years. The use of these medicines puts people’s health at risk, which can even result in death. It is estimated that 5% of the antibiotics on the market are counterfeit and that most of these are -lactams. Despite being a worldwide problem, its incidence is higher in less developed countries due to limited access to quality medical products at an affordable price and the lack of sophisticated means for their detection. Most of the techniques used to validate the purity of an antibiotic require specialized technicians, adequate infrastructures and expensive equipment, which makes it impossible to use in resource-poor countries. The main goal of this dissertation is to develop an inexpensive and user-friendly device, able to detect counterfeit -lactam antibiotics. This detection is based on checking for the pres-ence of the active pharmaceutical ingredient (API) in the antibiotic and verifying if it is within the correct dosage. The device consists of a paper-based platform, obtained by Lab-on-Paper technology, with an enzyme-free detection, based on the use of gold nanoparticles. In the presence of the API, the HAuCl4 is reduced and gold nanoparticles (GNPs) are formed, allowing a colori-metric detection. This reaction was tested with solutions of different volumes and concentrations of antibiotic and calibration curves were obtained, from digital analysis, to obtain the dosage of that antibiotic. Solutions of common drug replacements were used to verify if there is formation of GNPs without the API.