Rapid paper based colorimetric detection of glucose using a hollow microneedle device

Abstract

The monitoring of blood glucose is a key aspect of diabetes care in limiting the negative effects of hyperglycaemia to both the microvasculature and macrovasculature. Self-monitoring of blood glucose (SMBG) gives an indication of blood glucose at a specific point in time and is recommended to be carried out four times daily. However, due to the inconvenience and associated pain of blood withdrawal, SMBG is often carried out less frequently than recommended or not at all. Extraction and subsequent determination of glucose in interstitial fluid (ISF) using microneedles (MNs) is an emerging area of research due to their minimally invasive nature and lack of associated pain. In this manuscript, a novel method for the fabrication of a hollow microneedle device is reported. The microneedle produced had a sharp bevelled edge and was 400 µm in length. Additionally, a paper backplate embedded with a colorimetric system for the rapid visual determination of glucose in simulated ISF was developed and paired with the hollow MN. This device rapidly extracted simulated ISF within five seconds and its ability to produce a glucose concentration dependent colour change within 30 s was demonstrated. Using this approach, it was possible to discriminate between glucose concentrations in normal glycaemia (4-7 mM) and hyperglycaemia (>7 mM) ranges using the naked eye. While further development is required, the results herein highlight the potential of this device to be used as a blood-free minimally invasive approach to glucose monitoring.

Gelatin Methacryloyl Microneedle Patches for Minimally Invasive Extraction of Skin Interstitial Fluid

“…This improvement is the result of the excellent swelling properties of GelMA and the optimized prepolymer concentration and crosslinking time. While it may be possible to improve our design by incorporating designs such as hollow needles54 or other features,14,46,53 the fabrication process of our current GelMA MN patch is simpler. These swellable patches are easy to manufacture and can collect ISF from the skin rapidly, making them promising for clinical applications.…”

Engineering Microneedles for Therapy and Diagnosis: A Survey

“…However, the saturation time of the colorimetric strip is about 15 minutes, which is too long for in situ diagnosis. Using the same reaction between TMB, enzyme, and glucose, Nicholas et al used chromatography paper-based hollow MN to analyze glucose ( Figure 5A) [122]. A square paper submerged in glucose-sensitive reagent in advance was attached to the output of the hollow MN as a backplate.…”

Skin Biosensing and Bioanalysis: what the Future Holds

“…Analyte detection is typically by established electrochemical, fluorescence or colorimetric techniques. Here, innovative paper-based analytical techniques provide economical alternatives suited for lowresource settings [5,6].…”