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Winogradsky columns were invented by Sergei Winogradsky in the 1880s and have commonly been used as a microbiology classroom learning tool in K-12 and collegiate education. However, they can be challenging to examine with microscopy. We scaled down Winogradsky columns into nuclear magnetic resonance (NMR) tubes and replaced the natural sediment with a transparent soil substitute toward the goal of observing the microbial growth under a bright-field microscope without column disassembly. Using this “Mini Winnie” approach, students can practice their microscopy skills while observing microbial growth inside the column after only days of incubation on the laboratory windowsill. Overall, we believe that the Mini Winnies provide a simple method for maximizing student engagement while giving them a greater understanding of how microorganisms interact in the environment. 

A common biological theme on Earth is the importance of oxygen, regardless of an organism’s metabolic capabilities. This commonality makes the quantification of O₂essential in understanding life as we know it. There are many sensing methods that enable researchers to measure this important analyte, but not all sensors are compatible with every system. This perspective highlights common O₂sensing formats (and recent innovations) with the goal of guiding the reader towards a sensor choice for their desired application. We emphasize the importance of exploring unfamiliar metabolic processes, commercializing new sensors, and establishing collaborations for maximizing innovation and accelerating discovery. 

Ionophore-based nanosensors (IBNS) are tools that enable quantification of analytes in complex chemical and biological systems. IBNS methodology is adopted from that of bulk optodes where an ion exchange event is converted to a change in optical output. While valuable, an important aspect for application is the ability to intentionally tune their size with simple approaches, and ensure that they contain compounds safe for application. Lipidots are a platform of size tunable lipid nanoemulsions with a hydrophobic lipid core typically used for imaging and drug delivery. Here, we present LipiSensors as size tunable IBNS by exploiting the Lipidot model as a hydrophobic structural support for the sensing moieties that are traditionally encased in plasticized PVC nanoparticles. The LipiSensors we demonstrate here are sensitive and selective for calcium, reversible, and have a lifetime of approximately one week. By changing the calcium sensing components inside the hydrophobic core of the LipiSensors to those sensitive for oxygen, they are also able to be used as ratiometric O2 sensitive nanosensors via a quenching-based mechanism. LipiSensors provide a versatile, general platform nanosensing with the ability to directly tune the size of the sensors while including biocompatible materials as the structural support by merging sensing approaches with the Lipidot platform.