Glucose monitoring technology has been used in the management of diabetes for three decades. Traditional devices use enzymatic methods to measure glucose concentration and provide point sample information. More recently continuous glucose monitoring devices have become available providing more detailed data on glucose excursions. In future applications the continuous glucose sensor may become a critical component of the closed loop insulin delivery system and, as such, must be selective, rapid, predictable and acceptable for continuous patient use. Many potential sensing modalities are being pursued including optical and transdermal techniques. This review aims to summarize existing technology, the methods for assessing glucose sensing devices and provide an overview of emergent sensing modalities.

Trends in Biotechnology mass spectrometry (LC-MS/MS) (see Glossary) methods. Despite its high specificity, matrix interference may lead to falsely low or high results; that is, the matrix and co-eluting compounds can interfere with the ionization process in MS (via ion suppression/enhancement) [5]. Furthermore, the throughput of LC-MS/MS is lower than that of the conventional immunoassay platforms. Recent studies are either addressing these issues [6,7] or exploiting or improving this method's inherent advantages [8,9]. Accordingly, there has been a significant effort to increase the throughput of chromatographic methods [10]. Pioneering multiplex approaches have been reported for antiretroviral agents (ARVs) [11], antifungals [12], antineoplastics [13], antibiotics [6,7,14], antidepressants [15], and immunosuppressive drugs [16] in the past decade. More recently, ultra-performance liquid chromatography (UPLC)-MS/MS has been used for simultaneous quantification of antibiotics [17] and ARVs from plasma [11] and breast milk samples [18]. Another focus is the extension of TDM studies toward unconventional samples and sampling. Several LC-MS/MS methods have been developed and applied for hair [11,18], dried blood spots [19], urine [20], sweat [21], saliva [22,23], and tissue biopsies [24].

Background Enhanced methods of drug monitoring are required to support the individualisation of antibiotic dosing. We report the first-in-human evaluation of real-time phenoxymethylpenicillin monitoring using a minimally invasive microneedle-based β-lactam biosensor in healthy volunteers.