University of California

Illumina Corporation

Shawn O Meade

Michael J Sailor

Mark S Chee

Steven Mark Barnard

Bahram Ghaffarzadeh Kermani

Yang Yang Li

Todd Alan Dickinson

Anthony W Czarnik

Vijay S Kollengode

James Bierle

The invention concerns a particle having a code from a library of codes embedded in its physical structure by refractive index changes between different regions of the particle. In preferred embodiments, a thin film possesses porosity that varies in a manner to produce a code detectable in the reflectivity spectrum. An assay detection method uses such a particle and detects a spectral shift in the presence of an analyte. Additional embodiments are disclosed including additional features.

Optically encoded particles through porosity variation

The invention concerns a method of making a thin film and/or particle having a grey scale code embedded in its physical structure by refractive index changes between different regions of the thin film or particle, as well as thin films and particles made by the method. In a preferred method for encoding a thin film, a semiconductor or insulator substrate is etched to form a thin film including pores. The etching conditions are controlled to vary porosity in the thin film according to a pattern that will generate an optical signature in the reflectivity spectrum in response to illumination such that the optical signature will including a grey scale code. The etching waveform is formed by the addition of at least two separate sine components in accordance with the following equations (1)A=(A&#x2212;A)/2; (2) k=frequency=1/period; (3) y=A[sin(kt&#x2212;&#x3a6;)+1]+A(4) y=[y+ . . . +y]/n wherein equation (1) defines the amplitude of sine component n, which results in the spectral peak height, or grey scale of a bit; Equation (2) defines the frequency of the each sine component, which results in the spectral position of a peak, or identification of a bit (1st bit, 2nd bit, etc. . . );. Equation (3) defines sine component n and Equation (4) defines the composite waveform used to drive the electrochemical etch. The film can be removed and diced into particles.

Method for forming optically encoded thin films and particles with grey scale spectra

A method for forming photonic particles, where the method includes the steps of preparing a porous photonic material layer, patterning a soluble polymer on the porous photonic material layer, leaving dividing portions of the material layer untreated, infusing the polymer into the material layer, and removing the dividing portions of the material to obtain the photonic particles.

Polymer composite photonic particles

The invention relates methods of improving signal detection from an array and methods for background subtraction in an array. The invention provides for novel array compositions including arrays with wells with different shapes, or surfaces coated with reflective or selectively absorptive coatings. In addition, the array include a signal transducer element.

Array compositions for improved signal detection

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San Diego, CA, United States of America

Shawn O Meade