基于微膠囊的生物傳感器ppt課件

1、基于微膠囊的光學(xué)生物傳感器Microcapsules as optical biosensorsIntroductioncolor-changing particles reside primarily in the dermisrespond to changes in interstitial fluid compositionmeasurable shifts in their optical properties.external optical device pass light into the skincollectreflected or emitted lightperfor

2、m analysis to report interstitial composition to the patient in a continuous or spot fashionsmart tattooExamples of this concept : fluorescent microspheres/capsules, hollow fiber membranes encapsulating sensing chemistry, and polymeric slabs doped with fluorescent reagents.the target species are abl

3、e to freely diffuse into the container, while permanently compartmentalizing the sensing reagentsThe key to making this approach viable：engineer implantable materials, sensitivity, operational stability, and biocompatibility for long-term useEncapsulation within polyelectrolyte multilayer capsules N

4、ano-engineered microcapsule carriers is an effective means of encapsulating sensing reagents.Different approaches to entrap optical sensing assays: various types of microvesicles, including liposomes, polymersomes, and polyelectrolyte microcapsules. Polyelectrolyte microcapsules are formed by deposi

5、ting alternating layers of charged polymers onto sacrificial templates using the layer-by-layer (LbL) nanoscale self assembly process, which is followed by the removal of the template via chemical treatment.layer-by-layer (LbL) nanoscale self-assembly process allows for an even wider assortment of c

6、andidate materials.The goal of encapsulation is to trap the sensing reagents behind a semi-permeable Barrier.The sensor chemistry must be trapped in sufficient quantity for the optical response to be measured.Three principal methods:Precipitation, adsorption/absorption, diffusion1. Diffusion2. adsor

7、ption/absorptionAdvantage: virtually any removable template can be usedDisadvantages: low loading efficiency, requirement to use materials that can be induced to alter pore size, effects encapsulated speciesAdvantage: allows use of any polymers amenable to the LbL assembly methodDisadvantages: loss

8、of adsorbed/absorbed molecules during the LbL processExamples： PLL/PGA multilayer films on mesoporous silica (MS) spheres 3. PrecipitationAdvantage: high loading efficiencies, minimal concern over denaturation or other damage to sensing reagents, entrapped molecules remain stably entrapped during th

9、e LbL processDisadvantages: prepare templates each time encapsulation is performed, size distribution of coprecipitated particles is changed, large amounts of sensing reagents used in the coprecipitation process.Biosensors using PEM capsulesExamples： nano-engineered glucose sensor microcapsules base

10、d on glucose/galactose-binding proteinDifficult challenges Further work1 Mike McShane, Dustin Ritter, “Microcapsules as optical biosensors, Journal of Materials Chemistry, 20(2021)818981932 Aimin Yu, Ian R. Gentle, Gao Qing (Max) Lu, “Biocompatible polypeptide microcapsules via templating mesoporous

11、 silica spheres, Journal of Colloid and Interface Science 333 (2021) 341343 Tania Saxla, Faaizah Khan, Daniel R. Matthews, Zheng-Liang Zhi,Olaf Rolinski, Simon Ameer-Beg, John Pickup, “Fluorescence lifetime spectroscopy and imaging of nano-engineered glucose sensor microcapsules based on glucose/galactose-binding protein, Biosensors and Bioelectronics,