Lateral flow assays (LFA) are quick, simple and cheap assays to analyse a variety of samples at the point of care or in the field, making them one of the most widespread biosensors currently available. They have been successfully employed for the detection of a myriad of different targets (ranging from atoms up to whole cells) in all type of samples (including water, blood, foodstuff and environmental samples). Their operation relies on the capillary flow of the sample within a series of sequential pads with different functionalities aiming to generate a signal indicating the absence/presence (and, in some cases, the concentration) of the analyte of interest. In order to have a user-friendly operation, their development requires the optimization of multiple, interconnected parameters that may overwhelm new developers. In this Tutorial we provide the readers with: 1) the basic knowledge to understand the principles governing an LFA and to take informed decisions during lateral flow strip design and fabrication, 2) a roadmap for optimal LFA development independent of the specific application, 3) a step by step example protocol for the assembly and operation of an LF strip for the detection of Human Immunoglobulin G and 4) an extensive troubleshooting section addressing the most frequent issues in designing, assembling and using LFAs.

The COVID-19 pandemic made clear how our society requires quickly available tools to address emerging healthcare issues. Diagnostic assays and devices are used every day to screen for COVID-19 positive patients, with the aim to decide the appropriate treatment and containment measures. In this context, we would have expected to see the use of the most recent diagnostic technologies worldwide, including the advanced ones such as nano-biosensors capable to provide faster, more sensitive, cheaper, and high-throughput results than the standard polymerase chain reaction and lateral flow assays. Here we discuss why that has not been the case and why all the exciting diagnostic strategies published on a daily basis in peer-reviewed journals are not yet successful in reaching the market and being implemented in the clinical practice.

Water is the most important ingredient of life. Water fecal pollution threatens water quality worldwide and has direct detrimental effects on human health and the global economy. Nowadays, assessment of...

Monitoring of the human microbiome is an emerging area of diagnostics for personalized medicine. Here, the potential of different nanomaterials and nanobiosensing technologies is reviewed for the development of novel diagnostic devices for the detection and measurement of microbiome‐related biomarkers. Moreover, the current and future landscape of microbiome‐based diagnostics is defined by exploring the advantages and disadvantages of current nanotechnology‐based approaches, especially in the context of developing point‐of‐care (PoC) devices that would meet the international guidelines known as REASSURED (Real‐time connectivity; Ease of specimen collection; Affordability; Sensitivity; Specificity; User‐friendliness; Rapid & robust operation; Equipment‐free; and Deliverability). Finally, the strategies of the latest international scientific consortia working in this field are analyzed, the current microbiome diagnostics market are reported and the principal ethical, legal, and societal issues related to microbiome R&D and innovation are discussed.