Following on @jeffalk answer, please expand on your question.
In my opinion (and I've worked in aerosol science for a number of years) the main point of concern about ANY optical particle sensor around silica has nothing to do with the sensor itself but rather with the conditioning of the sample.
The hygroscopicity of the sample is particularly relevant as if it will absorb or adsorb water it will change its size. Low cost sensors in general don't condition the sample so they don't remove any water and that's why most of the "calibration" exercises done include temperature and humidity in their corrections.
The second issue is to do with accuracy of sizing. The counting of the particles is relatively easy, the sizing of them is where more assumptions are made, particularly about their shape. All "PM" classifications are defined in terms of "aerodynamic diameters" (the diameter of a sphere that has the same settling velocity) as size descriptors while their optical size (the diameter of a sphere that scatters the same amount of light) can be very different depending on the actual shape of the particles. So, I have no doubt that the PAII will see any particle that's larger than ~300nm but whether it will classify it in the correct size bin and then estimate the correct PM concentrations is a different question.