Rapid prototyping of a polymer MEMS dropletdispenser by laser-assisted 3D printing

In this work, we introduce a polymer version of a previously developed silicon MEMS drop deposition tool for surfacefunctionalization that consists of a microcantilever integrating an open fluidic channel and a reservoir. The device isfabricated by laser stereolithography, which offers the advantages of low-cost and fast prototyping. Additionally,thanks to the ability to process multiple materials, a magnetic base is incorporated into the cantilever for convenienthandling and attachment to the holder of a robotized stage used for spotting. Droplets with diameters ranging from∼50 μm to ∼300 μm are printed upon direct contact of the cantilever tip with the surface to pattern. Liquid loading isachieved by fully immersing the cantilever into a reservoir drop, where a single load results in the deposition of morethan 200 droplets. The influences of the size and shape of the cantilever tip and the reservoir on the printing outcomeare studied. As a proof-of-concept of the biofunctionalization capability of this 3D printed droplet dispenser,microarrays of oligonucleotides and antibodies displaying high specificity and no cross-contamination are fabricated,and droplets are deposited at the tip of an optical fiber bundle.

Innovations in measuring and mitigating phytohemagglutinins,a key food safety concern in beans

Phytohemagglutinin(PHA)is a seed storage protein and a type of lectin originally discovered in the common bean(Phaseolus vulgaris)for its blood-agglutinating effect.Due to its interactions with gut epithelia and digestive enzymes and its potential to trigger allergic reactions,PHA can lead to various symptoms in the human body.As a result,it has been regarded as a signifcant antinutritional factor in beans and other legumes.While several published works have summarized its structural,biochemical,and toxicological features,there is a scarcity of literature that reviews the detection,quantifcation,and reduction of PHA in beans,which is fundamental for the development of safer bean varieties.In this review,we present a comprehensive analysis of traditional and innovative bio-sensing methods for measuring PHA,including the recently available ultrapure liquid chromatography–tandem mass spectrometry and emerging aptamer sensor-based techniques,while discussing their respective advantages and disadvantages.We also revisit existing studies dedicated to creating PHA-depleted common bean varieties and explore the potential for reducing PHA content in beans without compromising their resistance to biotic stress.Additionally,we offer insights into the potential for controlling PHA content using the latest biotechnologies and breeding strategies.Overall,this review compiles rare and valuable information from studies that solely focuses on detection and depletion of PHA to shed light on and apply technological advancements in addressing potential food safety risks associated with the consumption of common beans.