## 1 Introduction  
Globally, enteric and diarrheal diseases are one of the most common causes of death in children under the age of five, second only to pneumonia [1; 2; 3; 4]. Though treatable and preventable, diarrhea is a significant problem in the developing world due to the scarcity of safe drinking water and sanitation. Studies of this problem point to a cycle of poor health and nutrition leading to susceptibility to infection by enteropathogens, leading to acute and prolonged diarrhea that exacerbates poor health and malnutrition [5]. This cycle must be interrupted by access to both well-established and proven treatments, such as oral rehydration therapy, and diagnostic tools capable of identifying causative pathogens and informing targeted treatments and preventative measures. Although the developed world possesses significant medical infrastructure for timely and effective diagnostics, technologies appropriate for low-resource settings have been slow to emerge. For the purposes of tackling the problem of enteric and diarrheal diseases, affordable, easy-to-use, and field-deployable tools are needed to replace conventional microbiological techniques such as culture methods that require substantial time, extensive training, and specialized facilities. In addition to high sensitivity and specificity, the ideal test platform should require minimal sample preparation and be capable of handling a variety of clinical sample types, a major challenge for diagnostics developers [6; 7]. Additionally, multiplexed detection is critical for diagnosing enteric diseases since co-infections are very commonplace [8]. Differential diagnostics is also important for pursuing the correct course of action; in the case of enterohemorrhagic _E. coli_, administration of antibiotics is counter-indicated, as it would cause the cells to lyse, releasing large amounts of toxin into the body. Numerous commercial diagnostic systems have been developed with screening kits aimed at the detection of enteric infections. These include the BD Max system from Becton Dickinson(East Rutherford, NJ, USA), the PanNAT system from Micronics (Redmond, WA, USA), the FilmArray system from Biofire Diagnostics (Salt Lake City, UT, USA), and the xTag gastrointestinal pathogen panel (GPP) assay from Luminex (Austin, TX, USA) [9]. Although these devices have been demonstrated as effective diagnostic tools, most are not designed for portable, standalone operation, as required for use in a remote setting. Additionally, limitations such as the need for large sample volumes, costly reagents, and low throughput prevent these technologies from having a significant impact on global problems such as diarrheal disease. Efforts in the field of microfluidics hold great promise for the alleviation of such global public health problems by meeting the need for reliable point-of-care diagnostics. Through miniaturization and integration of various bioanalytical processes, microfluidic technologies have the potential to offer rapid, cost-effective, and portable solutions to medical needs in the developing world [10]. Within the application space of enteric screening, a variety of microfluidic detection modalities have been reported, including electrochemical [11; 12], surface plasmon resonance (SPR) [13], and molecular methods such as polymerase chain reaction (PCR) [14; 15; 16] and loop-mediated isothermal amplification (LAMP) [17; 18; 19; 20; 21; 22; 23]. A notable subset of the microfluidic system types is centrifugal, or lab-on-a-disc, devices, first developed in the late 1990s [24]. The simplicity of operation, the lack of complicated external instrumentation for sample transport (e.g., pumps), the ability to easily eliminate bubbles, and the inherent capability of density-based separation make centrifugal systems uniquely suited for diagnostics at the extreme point-of-care [25; 26].