Paper, a key factor in food diagnostics

At the beginning of my career in the in-vitro diagnostic industry, I was attending a seminar in Milan on biosensors for the agri-food industry. It was 1988 or so. Many speakers told us that biosensor technology was going to allow the food industry to rapidly detect any kind of contaminant. I was impressed. As a young biotechnologist busy with ELISA kit development, I thought, “Maybe the ELISA will soon be replaced by faster and more efficient small instruments.” A few weeks later, some researchers from the clinical diagnostic industry told me that “ELISA plates will soon disappear.” Honestly, as a scientist, I had some doubts. And in the following 30 years, I saw a carousel of biosensors, bearing any kind of physical interface linked to the detector (bio) molecules, passing through a variety of B2B meeting and scientific conferences, some of them even presented as results of EU RD projects. The era of “endpoint” immunoassays, in any case, is far from over, I think. Many startups and even a number of giant players broke their bones trying to introduce all kinds of new biosensors into the food testing market. Whether, small, portable, or, more frequently, bench top, such instruments did not satisfy the needs of end users. Does anyone remember the Biacore?At the same time, yes, the “poor” microplate had a hard time, but certainly not because of biosensors. While tons of paper and rivers of ink have been used to claim the wonderful sensitivity of the new technologies, an “old” immuno- method, not even a real-time one, still holds center stage: the “Lateral Flow Device” (LFD). I am pretty sure the EU Commission has spent tens of millions of euros in the past 30 years to develop prototypes of sensors that are less sensitive than LFDs already on the market, but with longer assay times and, often, with more complicated sample preparations. Still, many applicants or startups write that they have a much more rapid method than existing immunoassay kits that require half an hour or more to get the result.What can we learn from this story? Small is fine? Simple is better? Well I do believe that forecasting the length of a technology lifecycle is very difficult. However, while we know that tech fashions are good for grant applications, they have little to do with the market success of a product. I am no longer impressed by the decision of large companies that sometimes follow this trend; small, experienced, specialized companies have little to be afraid of. The large companies come, they spend a few million, and with the same speed they disappear.Long life to end-point immunoassay. Paper-based LFDs are more and more efficient and reliable. Even the poor microtiter is going to have a new life with 2D simple array technology (while 3D arrays don’t look to me like the right system for screening purposes).